The real question is - Why did you play f5 instead of qh7 checkmate?
Why did I lose this game?

At least, that’s how I see it.

At least, that’s how I see it.
This is correct. Leaving the game is considered abandoning it.
This is correct. Leaving the game is considered abandoning it.
My opponent intentionally stalled because I would not accept a draw, do I switched apps while his timer ticked. I then check the app and I have an abandonment timer ON HIS TURN and lose the game. Ridiculous to let losers like this win by abusing a bad system. Why does my abandonment timer on his turn not stop since I rejoined the app?