I am creating a long-form document which depends on Smart Text Reflow working reliably. Unfortunately, it doesn't.
In my master pages section, I have three pairs of facing master pages: A4 landscape, A4 portrait and A5 landscape - so it's six pages. Each of these six pages has a primary text frame. The primary text frames on the left and right page of each pair are threaded.
When I create document pages based on the A4 portrait or A5 landscape template and add content, Smart Reflow will work as expected: New content creates new pages, deleting it will remove the empty pages. Great.
Applying the A4 landscape template, however, breaks Smart Text Reflow - no new pages will be added.
I went through all text frame settings. They are identical. The master page for A4 landscape has the "primary text frame" icon, left and right pages are threaded. I even deleted and recreated the primary text frames. It should work, but it doesn't.
I'm out of ideas; help would be appreciated. Thank you.