Savefile reverted

Platform:
PC
Description:
Savegame from Seam Cloud has reverted, also overwritten local savefile
Steps To Reproduce:
none, i do not know how
Images / Videos:
none
Host or Client:
local
Players in your game:
only me
Specifications:

I played an hour or so yesterday (march 26th), game saved normally upon exit. Started the game today (march 27th), and the game has reverted to an older state, as for how old i’m not sure how to determine, but a minimum of 20hours of playtime is lost, this include achievements, weapons and other resources gathered