I got the same bug - but I found a Way to delete the placed lots:
1st clear some space around the placed lot (in my case 2 tiles in each direction worked)
2nd place exact the same building(just 1more) with the same facing(alignment?) right next to it
3rd delete both buildings at the same time -
As I said - it worked for me - but I guess this is more a Tip for someone who does not want to delete a whole region
If you havent startet yet - just avoid this download