Downgrading the kernel to 5.8.100 and 5.8.7 did not solve the issue. On the other hand, when I downgraded kernel-firmware to version 20200827-1.1 the issue went away. I can try some other firmware version between this and the one I had before (20201005-1.1). I also noticed that a new version (20201005-1.3) is out, I can also try that if you think the problem may be solved already.