It's not just you and many others are experiencing the same issue. The daily task for upgrading homes should work regardless of the type of home you upgrade, but when the final week of the season started today there seems to be a glitch. Also there are tasks for watching ads, and the game won't play ads - this issue also started this morning, same as the task for upgrading homes - so both tasks are leaving us all stuck at the moment. I have reported this to the in-game customer service team, I would suggest others do the same.