Running Headers randomly applying incorrectly

[saxtonstudio]

I have a 200+ page book layout, all in one document, with several section markers in place for the different chapters. There are two pages (each in a different section) that will not accept the assigned running head like it does for the rest of the chapter – instead these two pages are applying the title of the subsequent chapter. All text boxes are linked and in their proper order. I have re-assigned the Master several times - sometimes (but not always) it actually refreshes the running head, but when I close the file and re-open, running head has reverted to the incorrect. 

Am totally baffled. Anyone know how to fix? (I know I can very simply change the header manually, which I may end up doing, but clearly something is wrong and I'd like to fix it!)

PS: I'm using InDesign 2024. on a Mac, OS Ventura 13.5.1

[Mike Witherell · Accepted solution]

Could it be possible that on those two pages where it is not working that the text is missing the paragraph style that triggers the running header?

[saxtonstudio]

THANK YOU, Mike!!! That was exactly it! Both of those pages are the ony ones that have photos only - so that was the common denominator which made your answer make so much sense. What a relief!