I live alone and don’t share my pc. I also dont log into my kong account from any other pc. I Don’t know when the change occured exactly,(within last few days i’d presume) but I just noticed that my avatar changed. Is it a kong issue?
If you avatar was one of the default one and you want to change back, try this game: Kongregate Default Avatar Picker
If it was a custom avatar, you can just change it back the same way you set it the first time.