How to display custom page numbers on the side (like in previous UI)

Hello everyone,

I have just migrated to the new UI and I enjoy it so far. Only one thing is missing: My custom page numbers aren't displayed on the side (formerly the top) like they used to in the previous UI. They still appear below the page thumbnails but seem to be missing when this panel is closed. Is there any way to bring them back?

Cheers!

New UI

Old UI