Help android device recent app button not working

[Livis]

Hi guy's,
suddenly i have a problem in my mobile my android device recent app button not working when i connect it to charger it works than after some time spend the recent app button again not working.
How to i will fix it.

 

[ocnbrze]

how does it not work? what happens" nothing? error? phone crashes? was this a recent issue? or has it been like this for awhile? or was this after an update?

just remember the more details we get, the better we can help you.