Chess960 bug

We'd still need a link. And you telling us on which move you were trying to castle.

I think its the game hes playing...

Because there he can castle queen side...I think

That's correct and I wasn't allowed to castle. I'm mystified why I was forbidden to castle.

I think this is the game OP is referring to. In the current position (after Black's move 14) White is able to castle queenside by putting Kb1 on Ra1.

Or just more simply. Place the king on the rook.

I tried to but Lichess wouldn't let me castle.

If you haven't moved the king or rooks, put the king ON TOP OF THE ROOK, not next to it. Placing the king next to the rook like in standard chess won't work I believe, but if you stack the king on top, then castling is possible.

There's also a "Castling method" setting in preferences - maybe it matters,
lichess.org/account/preferences/game-behavior

Chess on!

I have the setting on for placing the king on the rook and it still did not let me castle. I was under the impression that maybe I had moved the king but the answer is no I didn't.