Teams Project auto-updating for one editor?

Hi all, I'm working on a PP Teams Project with 2 other editors at the moment. One of the editors is saying that any time one of us Publishes, he's getting a forced auto-Update after a few minutes that's causing his current timeline to copy to a new timeline and his open timeline is reverting to an older version. Any ideas what's causing this? I don't think I've ever had a forced Update, I've always had to do it manually. Any help appreciated!