@HG: yes I mean this diagram on this page. If I promote the Prince to Queen, I can move it at his turn. But if I choose the promotion to Prince, then I do see a Prince on the diagram, at its turn I do see the red losanges and the yellow dots but I can't move the piece. The Prince remains stuck on its square on the last rank. This with Firefox, I'm going to check with Safari.
@HG: yes I mean this diagram on this page. If I promote the Prince to Queen, I can move it at his turn. But if I choose the promotion to Prince, then I do see a Prince on the diagram, at its turn I do see the red losanges and the yellow dots but I can't move the piece. The Prince remains stuck on its square on the last rank. This with Firefox, I'm going to check with Safari.