Image on separate page not working

Hi, I created a book using Vellum, which contains images. The images are configured in Velum to be 'on a separate page. Vellum outputs the book as a ePUB which when opened with Kindle Previewer looks correct. When I use the KFX Output Plugin in Caliber and move the KFX to a Kindle paperwhite or ColorSoft, the images are appearing in line within the text on the following page.

KFX output version 2.11
Calibre version 7.20

Thanks for any guidance

M