Hi Mike, thanks for doing the steps and posting the file!

But yeah it looks like these steps must not have been quite 100% exactly the same thing that you did before, because you've got all totally fine and all joined together solids in this result and not the same kind of problem as you had before.

So unfortunately I'm not really any closer to giving you any more information about your previous question about why you ran into that join problem before.

Thank you though for trying to set up a reproducable example - getting reproducable steps so I can see the problem actually unfold through the actions that caused it does greatly help for being able to figure out what's going on and if it's a bug or something in the geometry or whatever...

- Michael