Hello, @besboy 
I think I’ve seen a similar report regarding the use of roads, but I can’t find it…
As a possible workaround, if you have a previous savefile, load it and don’t connect the buildings with roads. Build them one by one, and once they are all built, draw the roads and build them. I think that should work (any forum user, correct me if I’m wrong).
Anyway, if you could upload the affected savefile to this thread: [A16/A17] The buildings my hearthlings will not build (round 2!)
the devs can take a look at your case 