Performance degrades after playing the game for a while

I am having this issue exclusively with all Forza games including FM7 on my pc where I would have normal 60fps all the time in the main menu and in a race but if I leave the race afterwards, my FPS would be locked to 30 FPS and GPU usage would jump to 99%

My pc specs are gtx 980, 16 GB ram and ryzen 1600.
I have no overheating problems whatsoever as monitored by MSI afterburner.
I tried reinstalling the GPU drivers, increasing the page files or disabling them entirely. Which don’t help still.

Lowering the graphics settings doesn’t help, only a game restart fixes it till it happens again.

Edit: I have fixed this issue by overclocking my ryzen 1600 cpu to 3.7ghz. now after playing 3 races and running the benchmark consequently, i no longer get performance degradation. which is weird considering that msi afterburner never showed 100% cpu utilization. anyways, hopefully this helps other people who happen to stumble upon this thread when googling this issue.

Edit 2: nope overclocking DOES NOT fix this issue. apparently when i overclocked last time, the game set the graphics settings to dynamic. that’s why i could maintain 60 fps. all i can say is that this is a serious bug with forza engine and this needs to be fixed.

This is happening to my games as well since the windows 1803 update. If you have the update that’s probably the reason. Wish I could get 1709 back.

Ditto the 1803 is a bit dogy for some reason