This is a PSA for those of you on XBL who are experiencing the eternal synch issue, sitting for hours while your cloud saves pretend to synch with you console, only to inevitably fail.
I finally "fixed" my problem, by deleting all my saves from the console and the cloud.
Manage game > Saved Data > Delete Everywhere
Start a new character. After that, don't keep more than five save files on your console, and in my experience) it will synch properly.
I know, I know. You shouldn't have to do this. You've put in a lot of time. So had I. I restarted from scratch four times trying to deal with corrupt files and clueless MS support staff, never made it past level 25, and I can probably scrap everything in Sanctuary hills in my sleep. I had high hopes that the updates to XBL and Fallout that just dropped would fix the issue. No dice. It's pretty clearly a problem on Microsofts end, I think. Trying to synch a console with a single FO4 save file to a cloud account full of old saves still takes hours to fail, when all it should be doing is marking files for deletion.
Your alternative is: Never be online when you start Fallout. If you avoid the synch trigger you can have as many local saves as you like and your only problem with them will likely be the occasional corruption issue. I feel your gamer-pain, but at this point there's really only these two options to 'fix' the issue in user hands until MS can get their act together. Nuke and pave, or stay offline when you load.
Back to vault 111 I go...again. At least I know how to begin this game in style now.