Can’t reproduce the bug, here is what I did in order.
Place the dining hall template down.
Create 10 chars are 4 tables.
Wait until all workers and hungry.
Build the dining hall walls.
Harvested Berries before the roof was started.
Workers went to sit down in the house with the scaffolding up.
Workers went through the scaffolding without problem.
Before the workers would definitely get stuck, but they seem to be fine. If anyone would like to test it on their game then here is the save file