Users are all stating they see a horizontal scrollbar. This isn’t a new thing.
I’ve looked into the CSS and I see a min-width of 375px applying. The mobile devices have a Viewport Width of 360px. This aligns with the stated experience.
I don’t know how this amount is being calculated or if it’s hard-coded somewhere (accounting for iPhones), but it’s one stated reason users are frustrated with using both the browser version on their phones and the mobile app, too.