some of the public variables in my scriptable objects change on their own on when i start up the editor

so I'm making a turn bases 2d rpg, and I'm using scriptable objects for character stats. they have a bunch of numeric stats, some strings, some lists of other scriptable objects( which I'm using for skills and equipment), a sprite for the in game portrait of the character, and the animator for that particular character. now this all works fine, when its all set up right it does exactly what I want it to do, the problem is that the don't always stay the way I've set them up. when I open the editor to work on the thing , some times the public sprite and animator I have set in the object will have changed to some random file in the project folder. the sprits will change to some other random image, and the animator will change to a mismatched file. I cant work out why this is happening, and it doesn't even seam to happen with any consistency. some times ill open it up and it will be exactly as I left it , other times I'll try to test something and run into an error because the character portraits aren't set. the only times in the project that the character sheet objects are written to are when i add to the list of equipment/abilities and when the numeric stats increase from levelling up. there is no code that I've written that changes the portraits sprite, or the animator. its not a big fix each time, but its getting annoying and I'd really appreciate if any one knows why this is happening , and/or how to stop it.