I keep getting the icon that my characters have been reset, but I don't see any real difference. Anybody know what this does?

Sorry, I would need a bit more detail. When does this happen? After a Mythos Effect?

It happens on the midnight effect. I have only noticed it after the Alaska expansion. An icon comes up, it looks like two green arrows within a circle, it says character reset.

I have looked at the character's health and sanity, as well as their inventory. I don't notice any difference. It seems to come up a bit.

Maybe it moved them from the adventures (if they were in any) to the camp so that if you failed an adventure with an entry cost, you have to pay it again.

I'm just guessing because I don't remember any sich mythos effect.