Help on image resizing

hello.
help on image resizing needed

replacing images on a Foundry starter site, no matter what i do i cannot get the height of the image to match each other, EVEN IF I USE THE SAME HEIGHT in pixels.

i am downloading large images (> 6000x 4000 px; 8-12 MB files sizes) from dreamstime.com, then opening them in Affinity Designer 2, exporting JPG files while specifying pixel height to 900, then place the image in Foundry stack. educe file size.

but the bottoms don’t line up - see screenshot.

I even have the sizing set at 1600x900 in Foundry stack.

no matter what, they don’t line up even if i change the image height to 500 pixels

any help would be appreciated