I have 3 simple objects: one cube and two cylinders. For some reason, I cannot get simple boolean operations to work.
One issue seems to be the fact that the union object has the same width as the target object. If I decrease the width of the union object slightly or move the cylinders a little bit out of their perfect position it works. Unfortunately, this is not what I want.
Finally, there is another issue. I cannot bevel the combined object, even if I apply the boolean modifiers first.
This is a link to the test file: https://www.dropbox.com/t/0YCbtRBy4TgEtHA4