You have to flip the board and promote upwards. I can't promote for black unless I flip the board.
I confirm the same bug, just wanted to create a topic, while I found this one. When you promote down (for black from white perspective) you see all possible pieces in the upper part of the board, all in 1 square, which makes manual promotion impossible.
Thanks for explaining this bug. We have duplicated it & will fix it.
It seems pretty fixed now.
