I don’t think so - have a search of the forum for “casting off circular problem” to find various discussions about the calculations Dorico does when coming up with the initial casting off for each layout, and why there are occasions when this isn’t ideal. Here’s one -
Essentially, Dorico thought that the first page could fit all the systems it’s put on it, but with the collision avoidance added on to the text objects and rehearsal marks, that turns out to be a tight fit.
There are a couple of things you can do that can improve things - firstly, reduce the minimum gap between text objects and the staff (Engrave > Engraving Options > Text > Vertical Position) but increase the minimum gap between text and other objects a tiny bit. That will let text sit closer to the staff but still not too close to anything protruding from the staff. It will also let rehearsal marks get closer to the staff, because the text isn’t pushing it so far.
Secondly, in Setup > Layout Options > Vertical Spacing, increase the inter-system gap to 12. This adds to the “minimum” amount of space Dorico allows between each system, and a cursory test in your projects suggests this prompts a recalculation of which systems fall on each page. In part layouts, I often bump this value (inter-system) up a bit - it also helps on non-vertically-justified pages to give a bit more breathing room.
Do also familiarize yourself with the available spacing defaults. Dorico does a pretty good job in a lot of cases, but feeling confident yourself in how you like well-formatted parts to look and how best to achieve that is still a valuable and necessary skill.
Lastly, you removed the flow heading on page 1 by deleting it, causing a page override - the better way to do this is to hide it.