You said you use P4000 now without any issue. And I believe your A4000 should be too.
Okay, while this might seem strange for some, I recommend you to try few older version of Nvidia driver, that is compatible with your Win 11. I’ll look further info for this in Nvidia logs.
I remember when I did some trial and error, mixing old nvidia drivers with newer one just to make my Tesla K10 working along with Quadro M1000M and T1000, there were some issues on some driver releases as either K10 or the Quadro couldn’t be detected properly by some software. However, after some efforts, they both were recognized and working properly.
Let us all know how you need anything, and we all be glad to assist, here 