User281315223 posted
Although I haven't used Crystal Reports in years, although it sounds like this might be the expected behavior based on this comment I came across:
Sub reports don't actually have page headers.
The pagination is controlled by the parent report, and the child doesn't have any knowledge of it. When a new page is reached, the page header from the parent (main) report will actually print, if I'm not mistaken.
If you have a look at your sub report, (even the on demand sub reports work this way) you'll see that they do not even have a page headder section.
I haven't used on demand sub reports very much, so I can't really provide a good workaround. Maybe try putting your header information in the group header in the sub report? Or if you're working inside an application can you make a call to another sub report?
(personally, I use hyperlinks to call my other reports, but I have an application hosting my report files)