I have been playing FO4 on my LCD deck over the holiday week, on/off the internet at times. I also finished a play session last night on the plane so I was extra careful to make sure my saves synced this morning before I did the SSD swap to my new OLED deck.
What did I do?
I booted my LCD deck up, before taking anything apart, “Cloud saves not synced”, cool, I’ll let it sync. Gave it a few minutes, even started the game, also did a system update. “Cloud saves synced”. Looks good. Never had an issue with Steams cloud saves before, so this seemed all fine to me.
Swapped my SSD and MicroSD out to my new OLED deck, go to load up FO4 to see its beauty on the new OLED screen, and behold, no cloud saves for the last few days.
I checked all through the prefix folder, no saves at all remain from my last few sessions, it completely wiped the profile folder and reset it to whatever was on the cloud. Nothing is left.
I wasn’t aware of this page below until I was doing some research for this, so my advice to anyone swapping drives between decks, if you’ve played a game recently do yourself a favor and confirm that its actually uploaded your cloud saves, cause the UI apparently cant always be trusted and some part of the system update process between deck can reset a games profile folder.