Buildings Complete, but missing some components

Hey all,

I posted this over on Reddit, but I’m running into a strange issue where a very basic template I made for a one room cabin completes (“Congratulations!”), but it’s missing its windows. The missing window changes from building to building. Here’s a screenshot below of two completed cabins with the template to the far right:

Checking the template, there’s nothing inside by those front windows that should block it from being completed.