New to doc sharing and having trouble

Hi - I am new to document sharing with Adobe DC and need to do this well for a new job so would really appreciate any help!  We are sharing through Google Drive and commenting in Adobe DC (free).  When I make a comment, the other person can't see it, and the last modified date doesn't change, until I download the pdf to my hard drive and upload it again to Google Drive in my files, and then finally copy it into the shared folder.  Surely I am missing something here as that is very cumbersome.  

Also, when I preview the pdf in Google Drive, only a few of the comments are visible, but often there is no Adobe option for opening the doc.  Now there is; a few minutes ago there wasn't and it doesn't change from opening or closing Adobe.  ???

Thanks!!