Game Auto-Resigned When Not Logged In

I was playing the following match blindfolded with a friend (en.lichess.org/u1cdUg9IPUgV) but we didn't finish it because it got quite late.

We were going to continue the match another time, however just last night my phone got a notification that the game was over, and that I had resigned.

Either this is a bug, or my account has been hacked. I changed my password just in case but I can't see any suspicious sessions in the security section of my account preferences, so it's probably a bug.

Thanks, username05.

this is mysterious. I have absolutely no relevant expertise, but am trying to get this more attention.

Any updates about this?

Could it be something to do with leaving the game for so long without playing any moves?