Garmin Edge 830 Fails to Upload Rides Over Cellular Despite Good Signal

I've been using my Garmin Edge 830 on some recent road trips where Wi-Fi is spotty, relying on its cellular data feature to upload rides automatically. Even though the device shows a strong LTE signal and I have a decent data plan, it stubbornly refuses to upload the ride summaries until I connect to Wi-Fi later. I've double-checked that the cellular subscription is active and data usage isn't throttled. I also tried restarting the device and toggling airplane mode, but no luck. I want the convenience of immediate uploads without hunting for Wi-Fi, especially during multi-day rides. Has anyone else faced this with Garmin's cellular upload feature? Are there hidden settings or firmware quirks that might cause this? Would switching SIM cards or resetting network settings help? Any ideas on how to get reliable cellular uploads working would be a lifesaver.