Yesterday I bought a new monitor to replace an old one, I had one 4k display and three 1080p displays.
I replaced one of the 1080p displays with a 4k one and now only three of them work at a time. When I go into Nvidia control panel and try checking the box for the 4th one it turns off another to do so, all of the displays refresh rate are set to 60Hz and I have no idea why it wont let me use them all!
In short, two 4k 60Hz displays and two 1080p 60Hz displays where only three work at a time with a GeForce RTX 4070.