Username changed – But, I didn’t change it

Today I couldn’t log into my site using my username and password.

when I tried to reset my password it emailed me with a username I didn’t recognize.

Another admin who had no issues logging into the site created a new username and password for me.

But, it’s really weird that my username changed out of nowhere.

I did a wordfence scan and everything seems to be updated and normal.

It seems like this is a hacker. Has anyone had something similar happen or can give advice?