Solution is to take FB out of the battery optimization.
Go to battery settings, open hamburger menu / dot menu. Select battery optimization settings.
Set app filter to All Apps. Find Facebook. Disable Batt Optimization for it. Done.

Dear Sir or Madam, my newly bought BV6000 phone suffers from a touch screen problem in roughly the area where the space key of the Android keyboard is normally located: It never reacts on the first touch. You have to touch repeatedly. It is not a Keyboard problem though. I turned on ANdroid Debuggin...