Why does the cylinder split the face when converted to sheet metal?

I wanted to convert this pipe to a sheet metal in order to do a weld connection for a static thermal analysis. I broke the face of the cylinder in order to get the convert to sheet metal feature to work but now I get 2 segmented faced on the cylinder. It allowed me to created a weld contact in analysis where i needed it but I think is causing issues down the line when I try to mesh the part for the analysis.

What could be causing this defect on the cylinder? I followed the CAD CAM Tutorials Youtube video "SolidWorks Convert to Sheet Metal Cylinder"

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