Odd thing is it's now doing the same on mine with no card in and trying onboard, mines possibly the psu I'm not sure but it's going to be a pain to change that again as it means taking my water loop out againMy card was also an MSI Shadow. I ended up returning it. I'm waiting to get a 5090 for a decent price - if I get the same error it looks like it's time for a motherboard replacement.