I think this is a bug, or maybe something wrong with my display settings.

The Total Number of Pages in the toolbar only shows up to 4 characters. The current page box doesn't show the full number either but at least there are dots to indicate something is not being shown.

Attached is an example where the file contains 40,000 pages but only shows as 4000.

Windows 11
Acrobat Pro 2023.008.20470
64-bit

Thanks