Weld vertices causes unsmoothing

[hilliard.cody]

I am trying to weld two vertices in Form workspace but when I weld the points together it causes unsmoothing of model.  I have tried several things such a turning symmetry off but unable to fix it.   I have attached two images of the problem.  Any help would be appreciated. 

[jeff_strater]

you've created an invalid model.  I'm not an expert here, but I suspect that you cannot just weld that one single set of vertices - that will create a non-manifold body.  Is your intention to close that entire seam, or to only close the inner parts of the circle?  You might have to create another thin strip of faces.  Please share your model here for more help.

[TrippyLighting]

Images should NOT be attached. You can drag them directly from the desktop into the message you are editing. On windows, screen\shots are copied into the clipboard and you can paste them from there directly into the post.

[TrippyLighting]

Welding vertices like you show in your screenshots does not cause "unsmoothing".

Fusion 360 simply switches from smooth-view mode to box-view mode as it cannot create a valid limit surface (the smooth result).

As you continue to close that seam by merging these vertices the view will likely return to smooth view mode.

Having said that, you should generally model 80% in box view mode, not in smooth view mode. At least until you have a better feeling for the behavior of T-Splines.

[hilliard.cody]

I was not able to get it to work but I switched to surface modeling and was able to create the shape I needed.  Thanks for everyone's help.