Query Loop – combining page category with custom post type

I want to create a query loop showing me a specific category of pages + a custom post type

I found on the forum a snippet to combine multiple post types in 1 query loop. But it does not work for me 🙁

https://ww.wp.xz.cn/support/topic/multiple-post-type-in-one-query-loop/

The moment I specify in the query block I want to drill down to a specific page category, the query snippet (called from the grid block) seems not to execute anymore. It looks like the merge_array does not append the result of the query block with what is defined in the snippet.

Help appreciated. //Luk