Definitely sure! Have a glass screen protector as well. It will minimize then go back to full size if more than 1app is open.
It's COMPLETELY doing my head in!
And this took forever to write!
Pleasehelp!!
The button itself might be faulty, then, which would require a trip to the repair shop. But just in case it's due to some 3rd party app causing problems, see if the problem persists in Safe Mode: https://support.t-mobile.com/docs/DOC-28008