In the bug report for the problem with Developer Mode on the Quest (https://developer.oculus.com/status/) there is a work-around that tells us to use ODH.
Can someone please explain where this option is? I have ODH, my device is connected and I see a lot of options, but not enable developer mode. I have a Quest 1 and fortunately for me developer mode is still working (I can see that there is a firmware update for my headset, but I will not install that for now), but I am supervising a couple of students that use Quest 2 and they can not progress with their work.
I had the same issue. They fixed the problem with the companion app (https://forums.oculusvr.com/t5/General-Development/Developer-Mode-Issues-Update/m-p/892227#M2012) but it wasn't working for me either.
I download the ODH app and when I setup a new device, during the configuration there is a step to enable the developer mode. Maybe be you can try to setup the headset again ?
I also have some students using quest 2 so I hope I will manage to setup again all their headsets.