why does lichess stop playing the best move in a lost position?

In lichess feature “Practise with the computer” the “computer” stops playing the best move once it reaches a lost position.

Kinda boring if you want to practise converting a won position to a mate. (For example: It is much easier to win with bishop and knight against a king if “he” lets me keep a pawn for no reason.) This happens all the time.

Why does it do that?
Can this be fixed?

I suppose I might as well ask for examples.

@Toadofsky said in #2:
> I suppose I might as well ask for examples.
I will try although it is not saved anywhere.
So you have to try it yourself:
in the position
lichess.org/analysis/8/4k3/4pb2/8/2r5/8/1p6/1K3R2_b_-_-_1_48
click the practice with computer
do the move (as black) Rook c1 check.

To avoid check mate for as many moves as possible Rook takes Rook would be the best answer.
Practice with computer plays a King move.
This is just one example.

I think Stockfish needs to use tablebases (syzygybases) in order to play the best endgame and late middlegame moves, however those tablebases are not available in the browser-based version of Stockfish.

@Toadofsky said in #6:
> I think Stockfish needs to use tablebases (syzygybases) in order to play the best endgame and late middlegame moves, however those tablebases are not available in the browser-based version of Stockfish.

Nah, the browser based stockfish easily finds the best move in the position.
It’s just PWC that doesn’t.
Someone designed this.

This needs to be fixed because the game will be really boring.

@Toadofsky said in #2:
> I suppose I might as well ask for examples.

If you need example I suppose you never tried to "practice with the computer". And if you never tried, try once and you will notice.
I find that thing really annoying, and it really doesn't look like sonething depending on tablebase.

When I analyse a game where I had, say, an advantage of +2.5 and my opponent resigned and I try to practise, then usually this happens:
When in the middle game, I very often lose my advantage, because the "practise with the computer" engine is quite strong. I also notice that it uses some time to make its move.
But at some time in the endgame, it just stops calculating, you see how it makes instant moves, and these moves are so obviously bad that no 1000 rated player would prefer them.