Mac.10.15.7. Problem sorting a Slideshow in Photos

See this user tip: How to turn an Album into a Slideshow and preserve the Sorting, 2019 Version

NOTE: it only works with the Ken Burns and Classic themes.

What template are you using?

I believe photos always randomises the slideshows, and doesn't have any sensible method of sorting.

The only way that works, is to manually drag/drop the position.

A bit poor but the best we've got.

Most of the templates are fixed. So it will rearrange images to fit the template. Only a couple aren not fixed.