Since yesterday (no settings changes made) D4 is using 90-100% CPU and I can barely take 5 steps in game. The only things open are D4, Chrome, and Task Manager. Closing Chrome has no effect. Task Manager shows D4 bouncing between 90-100%, usually 95-100. It drops a bit (75-80ish) if I click the mouse onto the 2nd monitor, as soon as I click back to D4 it jumps back up. GPU is jumping all over the place just standing in town but graphics are totally fine.
As I said, no settings changes made. I updated graphics driver just in case, no change. CPU temps are 49-59 min-max.
edit: No ray tracing, reasonable medium graphics, NVidia Reflex disabled.