Steps to reproduce:
1. Load CLAPi: Kee Bass (
v1.2.0 alpha1, Windows only).
2. Show Booster parameter in track controls.
3. Drag Booster circular knob in track controls -> So far, so good.
4. Show Prio parameter in track controls.
5. Drag Prio circular knob in track controls -> Goes from Last (index 2) immediately to Low (index 0) and vice versa, but it seems impossible to stop at High (index 1).
The same goes for other 3-state enum and int parameters.
With the VST2 version of Kee Bass this works fine. Do note that this isn't necessarily a REAPER bug, because I've just added CLAP support to my IPlug fork, so it might well be my fault.
EDIT: Same on macOS, except there even the Booster circular knob seems too sensitive, and sometimes even seems to move in the wrong direction (tested using the trackpad on my MacBook).
EDIT2: Kee Bass v1.2.0 alpha2 for macOS can be downloaded
here