Ideas
I’ve experienced this issue as well and wanted to share my findings in case it helps with troubleshooting. At first, I assumed it was mod-related and didn’t realize the root cause might be tied to the save file itself, so I didn’t look into it right away. When I switched over to another save, the problem didn’t appear there, which made me suspect something more specific to that original file.
After reading through the suggested fixes, I tried the workaround of entering the penthouse lots through a social event at a neighboring lot and swap them to regular residential lots, and that did seem to resolve the issue in my affected save for the moment. However, I was not able to reapply the residential rental lot type to the penthouses without the issue reoccurring.
I imagine the team is already aware of and investigating this, but I wanted to check if there’s been any momentum or update on this specific issue. It would be great to know if it’s still under review or if a more permanent solution is being worked on.