Well, I tried it again and it initually worked. I exported the Customer table and the changes were in it. But after a few minutes (synchronization, I guess), I exported the Customer table again and all Contact entries that I had imported had reverted to their original states.
Also strangely, when I pressed the "Changes Only Sync" button on the QB tab and then hit refresh, the time for the last sync remained at 11:30AM for over 90 minutes. Only at 1:04 did this change.
And still my imports didn't stick. To reiterate, manually typing into the Contact field results in permanent changes, while the upload doesn't work.
And finally, I have no conflicts in my Resolve conflicts, but who knows, one may pop up randomly in 15 minutes or so.
Please help - I've spent 5 hours today trying to get this crucial data update implemented but it doesn't work.
This seems like a basic function that should work.