I had exactly the same issue, with everything disabled, as window updates, anti-virus updates, energy settings, etc....but for ~4 weeks,
every time i was playing the PC minimized the game, as you know
HistorixGT mod doesnt allow us to ALT+TAB to restore the game screen,
which was a real pain....with the other games i had to do a quick shift screen. I was using BITDEFENDER anti-virus for almost 2 years, never had such a problem like this one. I unistalled BITDEFENDER and install AVAST,
and i can assure you that turned all my system much better, everything is working faster now. Dont really know what happened and why after almost 2 years working fine, i got that issue (some incompatibility for sure)
But now it works well.
Cheers
P.S. i´m trying hard to achieve my 25 posts