Steps to repro:
1. Open the attached project on OSX;
2. Open the "Night" scene;
3. In the Hierarchy select Spot Light gameobject;
4. Attempt to slowly move the object with using the scene view gizmos.

Expected result:
Gameobject is moved smoothly.

Actual result:
Gameobject position randomly changes when moving the gizmos. It looks like the Scene/Game view windows are being constantly refreshed. See the attached video.
Regression introduced in Version 2021.2.0a7.

Notes:
- Reproducible on OSX 10.15.7;
- Not reproducible on Windows;
- Reproducible in Version 2021.2.0a7;
- Not reproducible in 2021.2.0a6, 2021.1.0b10, 2020.2.7f1;
- The same issue seemingly happens in Game view as well, making it pretty much unusable for testing projects in Play mode/runtime.