Hopefully someone has had this problem before and can help me figure this out i have a 2080 Ti ftw3 ultra.
Until recently it was working fine i play FFxiv and was getting 144fps which is capped. For some reason after i updated to the new nvidia drivers 436.30 from 431.60 my cards power target wont go above 20% it is currently set at 100. Which also causes it to cap at 60 fps. My monitor works fine i had replaced the dp cables as well and have a few to rotate from that are working. This happens on either dp port on the graphics card. Anyone have any ideas what is going on with this?

You are definitely not the only one. I have experienced this same issue over the last 4 days. I was about to pull my hair out.
 
I ended up Uninstalling My Nvidia drivers and I did a fresh install of windows which fixed it.
However after re-downloading my mouse/keyboard software, Chrome, stream(and pubg of course), Nvidia Gforce experience, Installed the latest drivers and installed X1 it happened again. so I rolled back my system using a restore point i created right after i did the fresh install. 
I'm currently going through each change/install i made this last time, restarting my system and checking my frame rate to see if I can find the culprit.
 
I'll let you know what/when I find out exactly what is causing the problem for me.