After wading through several old posts concerning sheet metal corners, I still did not find an answer to my problem.

I have a 14 gauge stainless steel pressure gauge housing that I am trying to finish out. I had to create the piece as a solid and then convert to sheet metal. I am having loads of issues in the corners. I am using 2017 SP4.1

1) Even with setting the corners to "butt", leaving a gap of 0.01 , I am still getting a major gap:

Why won't the corners actually close up to the right gap?

2. If I use the corner tool to close the corners (using same settings that I used in the convert step, I can only get it to close the flat, non-curved surfaces. It will not close up the curved area:

It would not allow me to select the curved sections - notice that I even have auto propagation turned on...

So, what am I doing wrong and/or HOW can I fix this?