Pawn disappeared

I was playing a blitz game (lichess.org/dCzzj15o/black), and around move 19 my A pawn disapeared. I didn't think much of it, but later lost on time because the invisable pawn stood in the way of some other pieces i wanted to move. Is this a common bug?

after 5. cxd5 cxd5 you and your opponent kept 7 pawns until the end of the game, don't see anything odd.

Yes, you can't see it in the game recap ofcourse. I was just wondering if someone has exerienced the same thing.

Pungsaft I had my knights dissapear from the board in a game I played a couple of days ago. I had to close all lichess.org tabs in order to fix it.

Thank you for the answer Fuzzy. I'll try closing the tabs if it happens again. Do you by any chance remember if you made a pre-move right before they disappeared?

I made a move or a premove but I am not sure which. After the knights dissapeared I tried refreshing the game page, closing the game tab and opening a new tab and navigating to the game but nothing worked until I closed all lichess tabs. I use Firefox. This problem also appears sometimes when watching games. I remember that ChessNetwork has a video or two of Magnus playing the titled arena and the same thing happens when watching the game.

Silly silly pawn. Plays hide and seek and thinks it's invisible. But the players know it's there.
Like playing hide and seek with small children. Noobs hide behind curtains and think their foot are invisible.