Thank you belodion.
Jimmy Le1 - Good Lock has quite a lot of cool functions, especially the Routines, which allows i.a. to have the phone unlocked at specific locations (the Google setting that famously does not work) or connected to specific wi-fi or to set to rotate the screen only in specific apps and many more. Also the One Hand Operation which is basically the gestures, quite helpful if you do not want to constantly reach the bottom of the phone. And some other UI customization options.
For now I have uninstalled Nova Launcher (

) and this seems to be working as I didn't have the problem for over 24 hours (normally the problem occurs every few hours). We'll see it this lasts.