I do think it is a hardware fault and that the electronic components fail somehow. I personally think it’s a design error in the Pixhawk 4 Mini and that it should be fixed, since it seems to be a very common error in the forums, always with the mini and always without any crashes.
I think you should try with an external barometer as I explained here: Pixhawk 4 mini baro sensor 0 missing - #13 by Murray_Louw
This will be your cheapest and fastest option. You don’t even have to customise firmware if you are willing to manually start the baro driver through the MAVlink Console on QGC. Or you could buy a new Pixhawk 4 mini, or better yet, a different flight computer.