You must have had a temporary disconnection. It's a common enough problem that they wrote an article about it. Might be something simple...
Chess.com Bug

But IF it was a disconnect, when I reconnected I should be able to see his second move. In this case, white never made a second move, even after I supposedly reconnected. If white had a second move on the board, then I would agree your presumption is reasonable.

Looking at your game archive, it shows that your opponenent did make a second move: 2.Nf3.
You must have been disconnected somehow, even if the indicator showed your connection as being solid.
Ok I play a bullet game, my opponent plays 1.e4, I play c5.
We both have perfect connections as indicated by the system.
For some inexplicable reason, my opponent doesn't make a move. I sit there thinking he has left.
30 seconds later I am notified that I have abandoned the game, he is victorious, and that is that.
Screenshot below.
Is this common here?
I literally have no idea how I could have "abandoned" the game when I made only 1 move and simply waited for him to make a second move.
If the system did not recognize I had made a move, then it would have aborted, so the only explanation is that he played a second move that was never given to me.