The wrong piece forced into place creates confusion far beyond its own edge.

A piece that nearly fits is worse than one that clearly does not. It looks settled, so everything built around it inherits a small error, and the confusion turns up somewhere else entirely, far from the actual cause. Hours then get spent examining the parts that are correct.

When several things are not working at once, look for the one you forced. Undoing a single confident decision usually resolves more than continuing to adjust everything downstream of it.