No Page Break After Part

My latest novel includes parts (Part One, Part Two, Part Three).

When I compile using my “DOCX Proof” format, there is no page break after the Part. It looks like this:

[attachment=2]Screen Shot 2021-03-23 at 2.00.02 PM.jpg[/attachment]

With the PDF, everything is fine:

[attachment=1]Screen Shot 2021-03-23 at 2.00.41 PM.jpg[/attachment]

Here’s the formatting dialog:

[attachment=0]Screen Shot 2021-03-23 at 2.02.53 PM.jpg[/attachment]

Can someone point me in the right direction? Thanks.

Two different Compile formats, I assume? You probably don’t have the same Separators settings in both.