Missing blunder for self checkmate in Antichess

[Boubou78000]

Exact URL of where the bug happened

https://lichess.org/qYqsDvoG/

Steps to reproduce the bug

In Antichess, have a forced checkmate and stalemate your opponent.
Analyze the game. (Server analysis)

What did you expect to happen?

The last move to be a blunder, because you were in a winning position and you lost on your move. (Mate in 8 => 0-1)

What happened instead?

The last move isn’t a blunder.

Operating system

Windows 11

Browser and version (or alternate access method)

Firefox for Android

Additional information

No response

[jxu]

Is this an issue with fairy stockfish or lichess?