Nova Launcher double tap to lock screen

[gregorkompara]

Hi,

I'm using Nova Launcher Prime latest version on my SGS8 on Oreo. I configured the double tap to lock the screen and chose the method with timeout because I'm using fingerprint unlock. When I double tap the homescreen the sreen goes black but then the screen doesn't lock after a few seconds like it should. It's just dimmed but not locked even after 20 or 30 seconds or seemingly forever. I don't know what the problem is but something is keeping the screen from locking. Any ideas?

Thanks!

EDIT

I found the problem, it was one of my apps which, when running, was preventing the screen from locking.