wireless – 5GHz wifi connection fine, but causes interruptions/disconnections with Bluetooth

I know that Bluetooth issues are common with Ubuntu, but none of the questions I’ve seen have the same underlying symptoms.

If I’m streaming a film while using Bluetooth, the Bluetooth connection stutters or drops entirely, sometimes requiring a reset, or pausing and starting the video to restart the audio connection. If I decrease the resolution or FPS on the video stream then the Bluetooth connection drastically improves.

I don’t understand why this would happen. As I understand it, Bluetooth uses the 2.4GHz band, and yet I’ve set my router to only use 5GHz.

How would I start to diagnose this?