Force staff to rely on system breaks only

All right
I am transcribing from a paper score and I want the dorico version to respect exactly the paper version.
For some reason the software keeps doing stuff ‘on its own’ without relying on system breaks only.
As you can see below bar 12 occupies a whole system. Not only this is ugly but also very annoying.
I did untick the fixed number of bars ber system in the Casting off options.
I really cannot fathom why I keep wasting hours on stuff that is so… elementary.

Any ideas on how to do this ? Using Dorico Elements 3.5

Somebody asked this on reddit already but it involvers engrave mode, which I dont have

Thanks in advance for your help

Welcome to the forum @xii !

Dorico is probably calculating that based on the amount of horizontal space required by those 4 bars plus the upbeat, they wouldn’t fit in one system. The upbeat, the start repeat barline, and the D# are probably nudging it over 100% horizontally full.

Try reducing the minimum note spacing for the layout in Layout Options > Note Spacing. You can still insert system breaks wherever you need, but allowing notes a bit closer together by default means more music “can” fit per system.