Forcing multiple systems onto the same page

I was wondering if it was possible to force systems together on a page. Also, when I do get more than one system on a page, why isn’t the divider showing to separate them? This is an orchestral score, btw. Thanks in advance for the help!

You can select the notes you want to be first and last on a page and choose Make Into Frame. This inserts frame breaks before and after. The first break is set to wait for the next break, so all music between them is forced into the same frame.

This can easily result in collisions, so you might want to experiment first with reducing the vertical spaces slightly in Layout Options > Vertical Spacing > Ideal Gaps, and/or the space size and margins in Layout Options > Page Setup.

Preferences for that are in Layout Options > Staves and Systems > System Dividers.