Can't buy some rental lots.

Hi there, I recently bought "For Rental" and I find myself unable to buy some rental lots. I have not tried in many other locations yet, but I cannot buy the Rental Lots in "Uptown" "San Myshuno".

It always tells me that all lots are unavailable. If I invite the Landlord to my current lot and then add them to the family, either through conventional means or through shift+left-click then they are not the landlord anymore and a new randomly generated sim becomes the new landlord.

Is there a way for me to actually become the landlord of those lots or is it impossible?

Thanks in advance for any good advice.