Zlain, I believe it is working as designed at this point. Can you describe the bug you think you're experiencing?
Lady of the Lake, there is no way around having to redo the cache if you make a change. That's a fundamental limitation of a population cache. You should not enable Population Cache on any population while you are still frequently adjusting it OR any other shader that might affect it (for example displacement or mask shaders). Population Cache is meant to be used only once a population is "finalized" or nearly finalized, and thus you can "fix" the population instances where they are and not have to repopulate them again if, for example, you reload the scene, or send it to a render farm, or are rendering an animation, etc.
- Oshyan