Comment 15 for bug 1945221

Try changing to the powersave governor. If something else set another pstate request and the intel_pstate driver doesn't know about it, then with the performance governor it might never send a new pstate request.

All of this is very similar to a few months ago, on askubuntu and the path of investigation is the same.
References:
https://askubuntu.com/questions/1360985/all-cpus-stuck-at-800mhz-ubuntu-20-04-3
https://askubuntu.com/questions/1366090/ubuntu-20-04-3-lts-significant-throttling-of-intel-i7-processor
https://askubuntu.com/questions/1379048/intel-pstate-driver-not-being-loaded-when-added-to-grub-file

To check all operating parameters I do not mean to use cpufreq-info. I mean do:

grep . /sys/devices/system/cpu/intel_pstate/*

and

grep . /sys/devices/system/cpu/cpu*/cpufreq/*

For posting herein, and as a long as you have checked that the repeated information is the same, the second one can be shortened to (choose whatever CPU you want):

grep . /sys/devices/system/cpu/cpu2/cpufreq/*