I think I found the cause.
This file Manager: https://play.google.com/store/apps/details?id=com....
I was mislead by the fact that I put it "on watch" for another 2 weeks ago, but then somehow got distracted and forgot. And today first launched, and he apparently intensified. And in my head I was sitting "well I anything new did not put."
Judging by the reviews, I'm not alone.