Optiplex 7070 and Airpods

I have just bought an Optiplex 7070 Micro (full details at end).

My Airpods 2 connect, but drop out after 5-10 minutes, and I need to manually disconnect and reconnect.

Same behaviour with PowerBeats Pro.

Sennheiser Momentum 2 wireless headphones work ok, though at about 10 minutes into a YouTube vid I heard a crackle (about the same length of time the Apple devices cut out).

The Airpods and PowerBeats have been working fine with my HP Pavilion laptop, and of course my iPhone.

One similar request has produced the idea to turn off Audio Enhancements, but this does not work.

Dell reps are inclined to wave this away as an Apple problem, and it could have something to do with the Apple implementation of Bluetooth, but I would NOT be happy with such a reply, since these are a pretty widespread device (even more so in the Age of Zoom), so Dell should have tested with them, and Hewlett Packard have shown it is possible to make a PC work with them. Did I choose the wrong brand of PC?

Dell Optiplex 7070, i5-9500T, Windows 10 Pro OS build 18363.1256, I've run the Dell utility to check drivers.

Has anybody in the community found a solution, please, other than using an external Bluetooth dongle?