Is it just me or is there a bug?

I think you're right, it seems you can't replay all moves if you create a study from a game link like lidraughts.org/hoei4jH8

It does work if you create if you create the same study from the game's PDN though, like in lidraughts.org/study/NV6gGdPM

I think that's what you mean? I'll look into it!

Replay bug of imported lidraughts games in studies has been fixed!