Hi @oliver.jackson, welcome back!
Are you trying to run 4 time 8k resolution through one RTX A6000? That is sadly not possible, the max configuration is 2x8k at 60Hz.
But a single 8k monitor should most definitely work. One of the first suggestions, as you might expect, is to update to the latest driver version. Definitely does not hurt to try.
And to get a bit more details, could you check out this post on the Linux forums and provide the requested information listed there?
Thanks!