I've fixed the bug. Will be fixed in 22. Please confirm whether or not you had anything like this happened in simple output mode (not advanced output mode), because this particular bug seemed to be exclusive to advanced output mode.
Sorry this one took so long. Sometimes certain bugs fly by me, especially when they're in something like advanced output mode which is less used (and really should be less used)
Sorry about late reply, I was outside of my city and couldn't test.
So, in current 21.1.2 version on a fresh profile:
1. Simple mode, default values. Keyint = 2
2. Advanced mode, default values. Keyint = 8
3. Advanced mode without enforcing, but with keyint = 0. Keyint = 8
Looks like simple mode is unaffected by that bug, but more and more users want to use advanced.