Why does my Keurig 2.0-400 shut off LCD screen when press BREW button

I have a Keurig 2.0-400 which frequently shuts off LCD screen when press BREW button? It works at times, but ive noticed it getting progressively worse. Sometimes it takes me over 8 to 20+ attempts to brew a cup of 8oz coffee.

Ive tried unplugging then replug machine. Ive descaled it. Ive removed water reservoir and cleaned it. Nothing seems to work. I lift handle, place a K-cup, close handle, select 8 oz or 10oz on LCD screen…press brew ‘Keurig 2.0” button, then screen goes to blank gray showing only the “power on” symbol to bottom Right side of screen?

anybody have this problem? any tips or pointers on how to fix? thanks in advanced