Boot Problems - FP3+ with E and Magisk

Booting system doesn’t function properly after installing magisk.

If I press the start button nothing happens. Reboot doesn’t function.
My solution at the moment: Every time I remove the battery for a short while. After that, the phone starts by pressing the start button.

How to can I fix this?

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

Keeping the power button pressed for about 15 seconds should force a reboot. This doesn’t work anymore?

Thank’s for this idea! I didn’t wait so long.
So this is functioning when normal start doesn’t.

And however, since two days, most of the time, the phone starts normally. I have no idea why.
But reboot still doesn’t work.
It’s very strange. I’ll watch it and report from time to time.
May be there are other people with the same problem.