When you split among multiple pages it will only allow one row or one column (depending on what you have set up) and will not use the rest of the available space on the page.
Graphisoft are aware of the issue.
You need to restructure your schedule and manually copy it to another layout - cropping the areas of the schedules you want to see on each page.
See this post for more info ...
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10