Hello everyone 
This is my very first post, and i’d like to greets all of you from Italy! I truly HOPE someone can help me out with this AWESOME emulator! I’ll try to be more direct as possible, please be gentle and easy!
So the problem is, from totally random day, my RA started to flickering hardly everytime i open it, while days ago everything was going perfectly! I will try to upload a gif taken directly from Nvidia recorder of what happens.
Everytime i choose Vulkan rendering, the screen goes crazy flickering, while if i choose for example D3D12, it won’t. But that’s what i want try to explain: i need Vulkan because i noticed the games (expecially DOS Pure) runs very smooth, like is 60fps and very stable, and lovely to see and play. I noticed only, if i disable the “Smooth Motion” from Nvidia App, it appears to stop flickering, but the games looks more “slow” and more 25-30fps style. This wasn’t happening before. I’ve tried even the new Nvidia Drivers ( 591.86 from January 27th) but it won’t help. I’ve tried even some options but nothing seems to work. I managed to randomly stop it by messing with options, but after i closed the game and back to main menu, the crazy flickering starts again. The one you see on the gif is only the menu, while gaming the flickering goes even faster and unplayable 
I’ll give some detailed specs, hoping in some help! I’d just like to use RA with smooth motion and vulkan like i did until few days ago!
Intel Core i7 14700KF 64GB DDR5 6000mhz NVIDIA MSI GeForce RTX 4080 SUPER (no oc) Gaming Trio X 16GB Windows 11 25H2 Original License GeForce Game Ready Driver version 591.59 RetroArch 1.22.2
If you need more settings or specs just tell me, hope you can see the gif and help me out, thank you everyone! Ciao!

I honestly never could guessed that was this the reason, this explain why in Win10 with same settings and hardware worked! Thanks again, finally i can play again Keen 4 very smoothly! I will never ever update anything again. Thanks again! ^^