Bluefin with 2 x 4090 but only one visible?

Hey all, been watching Universal Blue for a while and just started using it on my Laptop (Dell7780) and its working great!

My issue at present is with my desktop that has 2 x 4090 and nvidia-smi only shows one of the cards

Can anyone point me where or what I should be looking for with respect to this as its the first time I ahve ever used 2 graphics cards

Regards
James

I have done lspci and find only one of the 4090 turn up there so looks like it could be plugged into a slot thats unsupported…

My understanding is they should just work with the drivers already included in Bluefin…

I will keep investigating but loks like its going to be hardware related…