Hi there,
I followed your steps exactly and it solved the issue. I was in the middle of the process you described, but when it worked on my first vault I stopped w/ the screenshots. The difference that you suggested from what I had tried was changing the global graph settings first (mine were already correct on desktop so I had not been doing this) and not viewing global graph view in mobile when opening.
Solution as follows:
Open desktop global graph view
Change settings
Ensure sync complete
Open obsidian mobile ensuring page being opened is not global graph view
Open global graph view on mobile
Changes sync