"Disconnecting" at the end of the game

Hi,

I was playing weekend league this morning and i was 8-4 ahead at the end of the match. 

Referee blows the whistle for the end of the match, screen changes to post match details and then i get kicked out and match counts as a loss. This happend a few times now in several months. 

Now my win doesnt count. And as im not that good(div 4 player) its very anoying...

I need my win EA😅

Video added to show what happend...