I found about ~100 clocks on my L5. “Help” on “Clocks” instructs touching a clock, then pick on delete. That does not seem to get rid of the clock. Maybe why the “Usage” app indicates curves at +80%, when I am not using my L5 for anything?
So I used the “force quit” for processes to quit world clocks and then opened Clocks and found no clocks running. Back in “Usage” the curves were still high.
Tried that, it does not work on my L5. So had to use the other hack. My L5 is full of such glitches, Often the scale of fonts scales down for no reason, except that I seem to have hit an obscure combination of icons inadvertently. Then, when I am in the middle of editing a phone contact, the phone directory disappears for no reason and I have to start over, after rebooting, to clear some obscure cache. That is OK, I am retired and have time for what would otherwise be an inconvenience or nonsense.
That is unexpected behavior, you may want to consider reflashing your Librem 5 with a new image to start from a clean slate - it may clear up your issues.