acf gallery using multiple posts

I’m trying to post the gallery of a post type on a second post type (of different name). I have a post type called products. I want to show installation photos from the post type installations. I will have multiple installation galleries that all are related to the same product. when I use this code:

[ajax_load_more acf="true" acf_post_id="16053" acf_field_type="gallery" acf_field_name="image_gallery"]

I am able to get the gallery showing for that specific page.

However if I try to add a second post ID into the shortcode:

[ajax_load_more acf="true" acf_post_id="16053, 16027" acf_field_type="gallery" acf_field_name="image_gallery"]

Nothing gets displayed (yes both ids pull photos separately). Is there a way to pull the ACF galleries from 2 separate (install) posts?

I tried this too (changing acf_post_id to post__in) but got no results at all.

[ajax_load_more acf="true" post__in="16053" acf_field_type="gallery" acf_field_name="image_gallery"]