Domoticz

I've had a bunch of Aqara devices running fine for over a year until recently when a light switch decided to just start randomly turning itself off. There's no regularity - sometimes it's 10 minutes and sometimes it stays on for several hours.

I've not changed anything on my network, but I would say it started around the time I had new smart utility meters installed - they use ZigBee to communicate with the in-home display. Is it possible this is causing my problems?

I think it's not your problem.
If you have interferences you will have malformed requests or missing one, not a good one with a "turn off" request. Zigbee use requests with encryption/verification/numerotation, ect ..., impossible using a request from another network by error.

If you have the problem only on the bulb, make test with it.