Sajin
Have you tried running display driver uninstaller to clean out your current drivers, and then install clean with the latest drivers afterwards? If no, try that.

redteamgo
Sounds like a pretty funky issue. Just a few thoughts. Good luck….

Have you tried switching the primary and secondary card PCIE slot order on the mobo just to see if you can get signal to those displays? Worth a try for ****s and giggles for some kind of hardware conflict

Do you have this issue on regular boot or just reboot or all circumstances?

Have you tried eliminating the simultaneous use of iGPU and discrete gpu?

Did you do any mb or gpu bios flashes recently?

Do you have any windows rollbacks available from the approx time the problem began? (Maybe indicator of windows update causing an obscure display issue ?)

ocstagetech
In retrospect, it appears my Asus ROG STRIX Z490-E GAMING motherboard was simply dying. After trying all of the above suggestions with no improvement, I even did a fresh windows install and the bug persisted. 
 
After deciding to just live with it, 3 days later the mother board just died, no errors, no post, nothing, it just wont power on. Pretty sad seeing it is less than a year old.

getalife

ocstagetech
I am running a dual RTX 3090 FTW3 ULTRA GAMING set up with 6 displays. The main gaming/rendering monitor runs on the primary GPU and the other displays are all connected to the secondary GPU and the motherboards Igpu.
 
I recently had a BSoD loop caused by nvlddmkm.sys It created a boot crash loop that not even windows recovery could fix. I ended up having to remove both my GPUs and boot into safe mode. I was then able to uninstall all NVidia software and drivers, reassemble everything and boot normally.
 
The problem now is that every time I reboot the PC the monitors attached to the second GPU do not turn on. Windows and Nvidia control panel see that they are there but they are listed as Generic monitors with all options grayed out. I go into Device Manager and manually disable then enable the GPU and everything works then perfectly. The GPU functions normally the entire time, all rendering software sees and uses it, games will even use it as a physicx accelerator, heck even excavator sees and uses it. But it will not output any video to the displays until being disabled/reenabled.
 
Both GPUs work normally by themselves but as soon as they are both installed this occurs.
 
I have the latest drivers, firmware, and all updates installed. I'm not sure what triggered the original BSoD but I suspect it was a windows or Nvidia update that went off on its own. (it has worked perfectly for over two months)

Any help or ideas would be great, I have tried everything I can think of. I really DON'T want to have to do a full windows reinstall so I'm hoping someone has a better solution.
 
The specific cards are:
24G-P5-3987-KR (Primary)
24G-P5-3987-RX (Secondary)
 
PSU:
220-GP-1600-X1
EVGA SuperNOVA 1600 G+

Motherboard:
Asus ROG STRIX Z490-E GAMING ATX LGA1200
 
CPU:
Intel Core i7-10700K 3.8 GHz 8-Core
 
 
 

Sorry but i have to point out your motherboard unfortunately, you experiencing in my opinion a lack of power from the PCI-E slot and make those BSOD or failed to initiate properly your second RTX 3090.  You should ask Asus Engineers they might have a way to make it work...