Budget Router Keeps Dropping Wi-Fi When Multiple Devices Stream HD Video

I recently bought a budget-friendly router (TP-Link Archer A6) to replace my old one, mainly to improve Wi-Fi coverage in my small apartment. The problem is, whenever my partner and I both stream HD videos on our laptops simultaneously, the Wi-Fi connection starts dropping for a few seconds every 10-15 minutes. It’s super frustrating because the videos buffer or pause constantly. I’ve tried updating the router firmware, changing Wi-Fi channels, and limiting the bandwidth for gaming consoles, but the issue persists. We only have about 5 devices connected in total, so I don’t think it’s an overload. My internet plan is 100 Mbps, so speed shouldn’t be the bottleneck either. Is this kind of intermittent drop common with budget routers when handling multiple HD streams? Would switching to a dual-band router with QoS settings help, or am I better off upgrading to a mesh system? Also, are there any settings or tweaks I can try to stabilize the connection without spending too much?