[NiLuJe]

By blank, you mean a white screen, right?

Check your screensaver settings, in particular the "Hide reboot/poweroff message" one in [Gear] > Screen > Screensaver > Settings > Message settings.

(There's a very vague chance it might be buggy and affecting the full set of widgets, given that this is a weird option that probably barely saw any testing given how annoying it'd be to test).

EDIT: Doesn't look like it could be a problem after looking at the code, though.

My best guess would be the refresh simply being lost to the tides of time, possibly because of the Libra 2 "please don't crash on us" EPDC workarounds.
(And I'll chuck the fact that it worked on your previous device to gremlins (or, more likely, temperature changes affecting the screen's latency)).