I had the same issue with a vacation rental lot in Mt. Komorebi. Not only that, but all the other community lots I had converted into residential lots eventually reverted back to their original types — bars, cafés, and so on. And of course I couldn’t access these lots and Sims anymore.
You can fix this by first moving the household out via Manage Worlds to any other lot. Then, return to the affected lot and manually set it back to residential. However, I noticed that for this to work properly without rolling back, there are two important things you shouldn’t do:
1 - Don’t change the lot type directly from the Gallery. For example, if you download a bar and want it to be a residential lot, don’t place it down as a residential right away. Place it as a bar first, and then manually change it to residential afterward.
2 - Don’t switch straight from a community lot to residential. This often causes the game to revert it back to the community lot and can even break your lot or save. Instead, change it to something like Tiny Home Residential or Haunted House Residential first, and only then switch it to regular residential. I don’t know why, but ever since I started doing that, it’s been working without issues.
I hope this helps you! :)
I observed the same issue, but found a workaround if you have already placed a residential lot from gallery onto a previously community lot type: If you accepted the lot type change that the gallery is offering you, you can still make it work, by then changing the lot type to tiny home and then back to residential. This works 100% of times for me - it seems like re-selecting the residential lot type fixes the connection.
