I just synced my iPad and Mac.
The same file has a date of 4 Jul 2017 02:09 in the Scrivener for iOS project icons and a date of 7:22 AM today in the Mac Finder. I have definitely opened the file since July of last year, but I didn’t open it this morning.
Another has a date in iOS of 4 May 2018 13:36, and in MacOS of 5 May 2018 at 3:11 PM.
What do the dates in iOS actually mean? It seems they cannot be relied upon to indicate when the project was last modified.