XBOX ONE Glitch? Days worth of save files gone?

[GootVanSquid]

Just completed the HRS-1084 mission, visited Groundbreaker and went to Scylla. for the first time. Landed on Scylla, stepped out of the ship, and saved, then stopped playing, and turned off XBOX. I turn the game back on a few hours later,  and it is showing the most recent save as something I completed days ago.
At minimum, 6-8 hours of gameplay lost.... this is so discouraging, I'm not sure I want to go through everything I did again. I don't think I can even remember what all I explored, etc. This is awful