Just recently, my framerate in video games has fallen quite a bit, but not in all games. I haven't made any recent hardware changes, so this is presumably a software issue. BeamNG seems to work fine, which seems to be a far more intensive game than Rocket League which is stuck at about 45 FPS. GTA V is stuck at about the same number. TF2 hover around that mark as well. My CPU is an R5 3600X which is not bottlenecking anything.
MSI Afterburner reports that the GPU is stuck at 961 MHz, but it's not throttling as the temperature never goes above 40 °C. Interestingly, when I close Afterburner, I (sometimes, but not always) get some performance improvements. The GPU benchmark Unigine Heaven, which previously hovered at about 30 FPS, now can reach well over 100 FPS and never drops below 60 FPS. TF2 goes back to the normal framerate I saw before this issue (I cap it at 120), but it still has frequent stuttering every few seconds. Rocket League and GTA V see no such improvement.
The GPU has no issues in other software such as Blender which maxes it out, hitting 100% usage and its max clock speed.
I have the latest version of my GPU driver and MSI Afterburner, and I'm running Windows 10 Insider Build 21313. Does anyone else have this issue?