Titanic Chess

[l1ttlewolf]

Titanic Chess is a 10x10 chess variant.
Each player has 24 pieces: 1 King, 2 Queens, 3 Rooks, 3 Bishops, 5 Knights, and 10 Pawns.
Pawns are placed on the third row.
Second row: RNBNQKNBNR
First row: 1 Queen, 1 Rook, 1 Bishop, and 1 Knight. On the first row the 4 pieces are randomly placed.
Here is the code:
[titanic_chess:chess]
maxFile = 10
maxRank = 10
pieces = KQQRRRBBBNNNNNPPPPPPPPPP
start_position =
?qrbn/rnbknqkbnr/pppppppppp/10/10/10/10/PPPPPPPPPP/RNBKNQKBNR/?QRBN
random_first_row = true

It doesn't work. I don't know why.

Shaffle Chess uses the same board and 24 pieces.
The difference is that the pieces are completely random on the first two rows, while the 10 Pawns remain on the third row.
This is some kind of Fisher Random Chess on a 10x10 board.

How do I make them work?
Many thanks.

[l1ttlewolf]

Ok. I got a response on Discord saying that random FEN is not supported yet. That must be the reason.