Odd issue with XTU and Undervolt

Ok, So I managed to get the system down to .145 UV all is stable, but noticed something odd with it in gen sense I started doing this. My fans once they spin up do not spin back down they come down to about 30-40% and just hold no matter if the system is at idle or not. They will spin up higher if demand becomes needed but they wont spin down any lower then around 40%.

Anyone ran into this issue or know how to fix it ? only way I can get them to spin down is a reboot.

Edit.
Also temps are...

Odd issue with XTU and Undervolt

Odd issue with XTU and Undervolt