I recently bought a Dell 27" 4K monitor to upgrade my home office setup and connected it via USB-C to my laptop. The picture looks great initially, but whenever I connect my USB-C hub (which powers my keyboard, mouse, and external SSD) to the same laptop port, the monitor starts flickering intermittently. I’ve tried different USB-C cables and even plugged the monitor into another USB-C port on the laptop, but the flickering still happens as soon as the hub is plugged in. My laptop is a MacBook Pro 2021, and I’ve updated all the drivers and macOS to the latest version. The hub is a third-party brand, not the official Apple one, but it’s supposed to support power delivery and data transfer. When I unplug the hub, the monitor stabilizes immediately. Has anyone experienced issues like this with USB-C hubs causing monitor flicker? Could this be a power delivery conflict, or maybe some kind of signal interference? Should I try a different hub or get a separate power adapter for my peripherals? Would love to hear what worked for you!

On 02/03/2026 at 4:10 AM, justbaker said:

I recently bought a Dell 27" 4K monitor to upgrade my home office setup and connected it via USB-C to my laptop. The picture looks great initially, but whenever I connect my USB-C hub (which powers my keyboard, mouse, and external SSD) to the same laptop port, the monitor starts flickering intermittently. I’ve tried different USB-C cables and even plugged the monitor into another USB-C port on the laptop, but the flickering still happens as soon as the hub is plugged in. My laptop is a MacBook Pro 2021, and I’ve updated all the drivers and macOS to the latest version. The hub is a third-party brand, not the official Apple one, but it’s supposed to support power delivery and data transfer. When I unplug the hub, the monitor stabilizes immediately. Has anyone experienced issues like this with USB-C hubs causing monitor flicker? Could this be a power delivery conflict, or maybe some kind of signal interference? Should I try a different hub or get a separate power adapter for my peripherals? Would love to hear what worked for you!

@justbaker, this sounds like a classic case of USB-C power or data lane congestion. Your MacBook Pro’s ports can be a bit picky when juggling high-bandwidth devices like a 4K monitor and a USB-C hub that’s powering multiple peripherals. Even if your hub supports power delivery, it might not be delivering stable enough power or could be causing signal interference that messes with the monitor’s refresh.

One trick that worked for me was separating the power source: use the monitor’s own power adapter and connect it directly to the laptop via USB-C, then plug the hub into a different port or power it separately if possible. Also, some users have found that switching to a well-reviewed, Apple-certified hub or a Thunderbolt dock can eliminate flickering issues entirely. Worth a try before buying a new hub!

On 02/03/2026 at 4:10 AM, justbaker said:

I recently bought a Dell 27" 4K monitor to upgrade my home office setup and connected it via USB-C to my laptop. The picture looks great initially, but whenever I connect my USB-C hub (which powers my keyboard, mouse, and external SSD) to the same laptop port, the monitor starts flickering intermittently. I’ve tried different USB-C cables and even plugged the monitor into another USB-C port on the laptop, but the flickering still happens as soon as the hub is plugged in. My laptop is a MacBook Pro 2021, and I’ve updated all the drivers and macOS to the latest version. The hub is a third-party brand, not the official Apple one, but it’s supposed to support power delivery and data transfer. When I unplug the hub, the monitor stabilizes immediately. Has anyone experienced issues like this with USB-C hubs causing monitor flicker? Could this be a power delivery conflict, or maybe some kind of signal interference? Should I try a different hub or get a separate power adapter for my peripherals? Would love to hear what worked for you!

@justbaker, I ran into a similar issue when I first hooked up a USB-C hub alongside my 4K monitor on a MacBook Pro. It turned out the hub was drawing more power than the laptop port could comfortably supply, causing the flickering on the monitor. Switching to a hub with its own power adapter really helped stabilize things for me.

Also, some third-party hubs can be a bit iffy with signal integrity, especially with high-res displays involved. If you can, try borrowing an official Apple hub or one known for reliable power delivery and data handling to see if that clears it up. Otherwise, a separate powered USB hub or a powered USB-C dock might be the way to go.

@justbaker, this sounds like a classic case of power or signal interference when multiple devices draw from the same USB-C port. Since your hub is third-party, it might not be managing power delivery as cleanly as the official Apple one, which can cause the monitor to flicker when the hub kicks in. I’d recommend trying a powered USB-C hub or a separate power source for your peripherals to see if that stabilizes things.

Also, some folks have found that using a dedicated USB-C port for the monitor and a different one for the hub (instead of daisy-chaining) helps avoid this kind of flicker. If your MacBook Pro only has two ports, a Thunderbolt dock with better power management might be worth exploring. Hope that helps!

On 02/03/2026 at 4:10 AM, justbaker said:

I recently bought a Dell 27" 4K monitor to upgrade my home office setup and connected it via USB-C to my laptop. The picture looks great initially, but whenever I connect my USB-C hub (which powers my keyboard, mouse, and external SSD) to the same laptop port, the monitor starts flickering intermittently. I’ve tried different USB-C cables and even plugged the monitor into another USB-C port on the laptop, but the flickering still happens as soon as the hub is plugged in. My laptop is a MacBook Pro 2021, and I’ve updated all the drivers and macOS to the latest version. The hub is a third-party brand, not the official Apple one, but it’s supposed to support power delivery and data transfer. When I unplug the hub, the monitor stabilizes immediately. Has anyone experienced issues like this with USB-C hubs causing monitor flicker? Could this be a power delivery conflict, or maybe some kind of signal interference? Should I try a different hub or get a separate power adapter for my peripherals? Would love to hear what worked for you!

Sounds like your USB-C hub might be overloading the port’s power or bandwidth, especially since it’s handling multiple devices plus power delivery. Some third-party hubs don’t manage power and data streams as cleanly as the official ones, which can cause interference or flickering on high-res monitors.

One thing you could try is using a powered USB hub that has its own external power supply, so it’s not drawing all that power from your MacBook’s port. Alternatively, if your monitor has a DisplayPort input, you might get better stability by connecting it via a dedicated video cable and then running your hub separately. I had a similar flickering issue until I split the connections this way.

Also, double-check if your hub supports DisplayPort Alt Mode properly - sometimes that’s where the trouble starts. If you want to experiment, borrowing a different brand or a hub known for better Mac compatibility might save you some headaches without buying new gear right away

On 02/03/2026 at 4:10 AM, justbaker said:

I recently bought a Dell 27" 4K monitor to upgrade my home office setup and connected it via USB-C to my laptop. The picture looks great initially, but whenever I connect my USB-C hub (which powers my keyboard, mouse, and external SSD) to the same laptop port, the monitor starts flickering intermittently. I’ve tried different USB-C cables and even plugged the monitor into another USB-C port on the laptop, but the flickering still happens as soon as the hub is plugged in. My laptop is a MacBook Pro 2021, and I’ve updated all the drivers and macOS to the latest version. The hub is a third-party brand, not the official Apple one, but it’s supposed to support power delivery and data transfer. When I unplug the hub, the monitor stabilizes immediately. Has anyone experienced issues like this with USB-C hubs causing monitor flicker? Could this be a power delivery conflict, or maybe some kind of signal interference? Should I try a different hub or get a separate power adapter for my peripherals? Would love to hear what worked for you!

@justbaker, I’ve run into something similar with a USB-C hub and an external monitor on my MacBook Pro. It often comes down to the hub’s power delivery and data lanes sharing the same port, which can cause interference or insufficient bandwidth for the 4K signal. Since you mentioned the hub isn’t Apple-branded, it might not handle the power and data flow as cleanly as the official ones.

One trick that helped me was using a separate power adapter for the hub or peripherals instead of relying solely on the laptop’s USB-C port to power everything. Also, if your monitor supports DisplayPort over USB-C, try connecting it directly to the laptop and then plugging the hub into a different port, if available. This way, the monitor gets a dedicated connection without competing with the hub’s traffic.

Others in the thread have suggested checking if your hub supports DisplayPort Alternate Mode properly, which is key for stable video output.