The Region in the initial attachment has experienced corruption somewhere along the way. I’d guess that the Region’s brep has an opposite winding than usual. See screencast.
A recent capability enhancement to AutoCAD has been the sub-object selection method for 3d Solids and Regions. Now a CNTRL + Select can isolate features to those entities to allow Move (Extend, and even Erase if subentity is moved off the entity), Scale, Rotate. No Copy, unfortunately.
Regions may have desirable qualities (MassProps) not available in Surfaces.
https://knowledge.autodesk.com/community/screencast/749ed8af-8f61-4c34-b92b-35bf0e421461
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May your cursor always snap to the location intended.