BUG- Framerate drops significantly if Automation is on

I did my first automated Aux send to a reverb just now on the Fairlight page, and whenever automation is active, my video playback becomes completely unusable and stutter-y. When I disable automation, playback is smooth again. If I leave the aux send level at 0dB sending the whole clip through the reverb, playback is also fine. Its only when automation is active that I get stuttery playback.

Issue is on Davinci Resolve 15b5 on Windows 10.

Just confirmed the bug on a fresh install of 15b5 on macOS High Sierra as well. Stability overall in 15b5 does seem much better on macOS vs Windows, but this bug is definitely there on both platforms.