Thanks for the suggestions!
There is no overclock applied at thet moment, either to the GPU or the CPU. The memory is on XMP, but I’ve tried it both ways and it makes no difference. Note that the original FTW3 3090 I had overclocked successfully in this scenario, and the FTW3 3080 also overclocks fine in this scenario, so that doesn’t seem to be the culprit.
In fact, I’ve even tried underclocking both the gpu memory & gpu core to see if it made a difference (alas, no).
As far as BIOS reflash, what the heck I’ll try that in the morning. Thanks for the suggestion. I’m skeptical, though, since the same GPU causes the same failure on two different motherboards with different chipsets.
It could be a driver / MSFS software update issue that occurred while the system was torn apart waiting for a new GPU I suppose, but if no other 3090 FTW3 owners are having trouble that seems unlikely.
Begins to feel like a hardware issue - although a really weird one since other programs don’t seem to have an issue. I will probably RMA it early next week without a breakthrough.
Really do appreciate the suggestions
B.