I've had this issue on Windows and Mac using Premiere Pro CC 2018.
Normal Local Premiere Pro Project: I have an MXF or MOV file. I add tags to the Dublin Core Keywords section and it creates a sidecar XMP file in the same folder as the footage or adds XMP data to the MOV file. I can place this MXF or MOV in other projects and still search this metadata. (I can also use it in my digital asset management software which is nice.)
Premiere Pro Team Project: I have an MXF or MOV file. I add tags to the Dublin Core Keywords section. It saves tags I can search for in this specific project, but does not create an XMP file so I can't use that metadata anywhere else. If I go to EDIT>TEAM PROJECT>CONVERT TEAM PROJECT TO PROJECT all of that useful metadata does not convert over.
My question is, where is this metadata being saved in the Team Project and is there any way at all I can retrieve it? Or is my only hope to import that footage into a normal Premiere project and redo all of that tagging?