Adding mapping channel bug?

Hi

i’m trying to add a 3rd mapping channel but it doesn’t work anymore. Any idea??

1st and 2nd work but if i try to add a 3rd one it’s no longer possible

i’m running Rhino 7 SR22 2022-9-12 (Rhino 7, 7.22.22255.05001)

Thanks in advance

Either make sure you have no channel selected already in the channels list, or make sure you give another channel number when adding that third channel.