I noticed this on my dell my old Dell XPS 13. It usually lives in a corner running
boinc, and I saw its performance was being throttled heavily.
tlp and rebooted. Issue fixed. I suspect there was some issue with tlp configuration, but did not look into it further. What's interesting is that my laptop was plugged in, and I would not expect tlp to have any affect when my laptop is not on battery.
For anyone that does not know, tlp is power management software, so removing it may decrease battery life.