Just Curious

how can you lose a game when your opponant does not have mating material...King bishop (winner) vs King Pawn (loser)

All I can see is a lack of fantasy for mating patterns.

If their king is behind their pawn in a corner and their opponent has their bishop on the correct diagonal and they have blocked the opponent's king's exit witheir king it is possible

Not possible on that board

I think this gets discussed from time to time if you're interested in searching the forums.

I don't know why lichess chose the rules they chose, I think it would be simpler for a computer to ignore the position and have a lookup table using material only to work out if checkmate is possible.

There are valid arguments for and against each rule choice, but each choice works both ways, you could get a checkmate with a king and bishop if your opponent has a king and pawn.

So it's also not a draw even if it's K+P (timed out) versus K+N/K+NN?

@TLNextChampion I just tested with the board editor and continue from here against the computer.
It wasn't a draw.

@h2b2 Yes, I tried the KP vs KNN too. Computer is even smart enough that it didn't take that pawn! (??)

@h2b2 Lichess chose the rules based on the FIDE laws of chess

You can lose on time, resignation or cheat detected.