I think You’re right, it is a mediatek chip and I used to add the USB device id manually to load the module, but with nixos 23.11 it started working automatically. I’m also running a preemptable kernel… Probably related now that I think about it :P
I should track down the firmware, that was one of the things I was looking into when setting up the device id hack.
I think this happened once before after uptime of about a week… But I didn’t get any information from that crash. Also, I’m remembering that some configurations were failing to see this wifi device and falling back to wired so maybe this has been a hidden problem since the new nixos release…
Thanks to everyone for your thoughts, it’s very helpful.