PDF permits "copy selection link" but the pdf is locked for further editing

I took an imported PDF

1. Converted the pdf to markdown (using the right click menu in DevonThink). I did not see any “quotes” or “backlinks” in the flyout menu
2. Converted the pdf to formatted note (using the right click menu in DevonThink). I did not see any “quotes” or “backlinks” in the flyout menu