The sync addon should handle this more gracefully, but it happens when the code applying the changes on the remote side thinks the objects were modified during the sync process. In this case, it throws a 409 to avoid accidentally overwriting changes someone else did. If you select “reset remote to local”, the force flag is set and the changes are applied anyway.
I still “hope” these are just leftovers of an incorrect sync earlier this week. Can you please try:
delete the 3 objects in Gramps Web (to make sure we get rid of any potential inconsistent state in the remote database caused by beta code)
Bug report 13816 (about the 6.0.1 reporting as 6.0.0) specifically mentions the About Box, not the XML export header’s created tag showing version="6.0.0"
The GitHub resources and the wiki Download page now have -2 download for macOS Intel and ARM. (The WordPress Download page is still outstanding.)
@csam Could you download the from the Wiki’s Download page and see if installing that resolves the Version difference for export (in addition to the About Box?)