Got another one, same as DieSoft’s issue. While Unioning a series of planks into a deck I negated two additional Parts and tapered the front half of the deck section shown. When I tried to Union that with the two negated Parts shown in the images, the negated Parts turned solid.
I tried spinning the Parts 90 degrees and resizing them but they keep Unioning this way.
I then tried moving each .003 studs in the Z axis and then it worked properly.
Just thought I’d let you know it’s still not ‘perfect’ but it is getting better. Kudos to you guys.