By corrupt do you mean crash on load, or are you getting any error messages?
When this happens it effects even older saves, that had previously worked fine?
You can increase the number of quick and auto saves kept in the Game section of the options, though it doesn't sound like the frequency saves get overwritten is a factor in this, if named save are also corrupted.
Have you been playing other games that write a lot of save data? A hard drive or memory problem with the Xbox could cause this, but in that case it should effect any game.
If you still have any saves from the last time this happened, please email supportdos@larian.com, with a description of the problem (or link to this topic) and a couple of the saves (or a Dropbox or Google drive link, etc).
You would need to transfer them to a USB flash drive first, and a third party tool is required to read drives formatted for Xbox One on a PC (
see here).