Kodi keeping display at 2160p even after 4k file is stopped

Having trouble figuring out the solution to my problem. I’ll outline:

If I play a 4k file, Kodi changes the display to 2160p upon playback. The issue is that once I stop the file from playing, the display stays at 2160p, meaning Kodi does the upconversion to 2160p which results in a picture that is definitely subpar compared to the TV’s upconversion process.

Set up:
4K TV
HTPC (Skylake, Windows, Displayport 1.2 to HDMI 2.0 adapter)
Surround receiver

I have Kodi set to output 1080p and change the refresh rate of the display to match the file. The desktop is set to 1080p as well.

Everything is perfect until I play a 4k video, then it stays at 2160p until I manually switch resolutions in Windows to 2160p then back to 1080p.