Common options - Page Setup

[FoggyKernel]

(If this is the incorrect forum, please re-direct me)

I have been using Calibre for a while converting .docx into epub output for inclusion on my Apple iPad (iPad Pro, 12.9-inch, 5th gen).

I have set in the Page Setup under common options for doing conversions to select the output profile for an iPad 3. Not sure if this is still the smart thing to do.

One of the items that has me questioning this, is that on my iPad I am noticing that if I rotate the iPad from Portrait to Landscape mode, the epub book seems to loose pages (or parts of pages). In Portrait mode, the complete text is present, but when in Landscape mode, a page seems truncated. I've notice this usually happens frequently around page breaks (always before the break).

I am wondering if 1) I am using the correct common option and 2) if it has something to do with the added page breaks (I always force a page break to start new chapters).

Looking for a bit of guidance and wisdom.