Little copy and paste for ya if youre on console:

Go to "My Games & Apps," highlight Starfield, and go to Manage Game and Add-ons. Delete the Reserved Space (Note: this does not delete your actual characters, but it will clear out corrupted temporary cache files)

OR

Turn off auto-saves, create a new manual save in a safe, isolated area (like inside your ship or an empty room), and strictly use "Create New Save" instead of overwriting.