I don't have a DGT board but maybe Fritz is waiting for the promoted piece to be placed on the square?
Pawn Promotion with DGT Board

Yes, that does work. You just don't get the 'promotion' dialog box like you would without the DGT board.
I've sent some logging to DGT though as I still think it's a bug. I've sent the below message to DGT.
I've been looking at the communication window on DGT and have this output from some testing.
Red is me moving the pawn to rank 8 for promotion, note that `legalcheck`log entry is missing - I waited some time in case it was delayed..
Green is me moving the King.
NB as you can see the board is stable before both moves.
21:09:59.538 Stable Bd-> 12P16K4k15p13
21:10:01.054 Stable Bd-> 4P24K4k15p13
21:10:01.054 append Move: before legalCheck
21:11:43.539 Stable Bd-> 12P11k6K10p21
21:11:43.539 append Move: before legalCheck
21:11:43.539 append Move: legalCheck OK
Hi,
Hi, I'm using Fritz 14 (32 bit) with my DGT Smart Board and have come across an issue where Fritz 14 won't show the move of a pawn to the back rank, every other move on the board will work fine.
My DGT drivers are the latest and DGT have confirmed from the log file I sent that they think their software is OK.
See screenshot link showing that DGT Rabbit has detected the move from b7-b8 but Fritz hasn't.
https://ibb.co/CJ47XD9
Has anybody experienced anything similar?
I've sent this to Chessbase too
Thanks
Steve