An important point, which isn’t documented properly, is that Bubble automatically (and silently) assumes that elements with roughly the same vertical offset are on the same “line” and tries to wrap them as the page width goes down.
What I see as of 2200 17 Feb are two lines of boxes. The first line has three boxes (equally spaced) and the second line has one box (on the left).
When the page width goes down the first line (of three boxes) starts to wrap so the right-most box (my trips) moves down below the two left-most boxes. Then the two boxes adjust to take up equal space on the line and the box that moved down to a new line does the same thing, putting it in the middle of the line it just created for itself.
If you click on group “my trips” in the responsive tab so that it turns orange you’ll see a set of justification boxes (left, center, right). If you select each one you’ll see the “my trips” box jump to the left, center, and right of the line it’s on.
Responsive logic is tough. You might have to totally swap out a “narrow” UI and a “wide” UI based on page width.