Breadcrumb on custom template

Hi all,
I have a custom template page that lists custom post types under a particular category and it doesn’t appear to be showing the breadcrumb correctly. The last ‘node’ in the breadcrumb is the title of a post.

I’ve followed https://developer.yoast.com/features/schema/pieces/breadcrumb/#api thinking I could manually add a breadcrumb to the array, but that doesn’t seem to work – even on standard post pages the breadcrumb doesn’t get changed using the example given.

Also tried using var_dump() on the wpseo_schema_breadcrumb filter to check the function is running (as the breadcrumb does show), but calling yoast_breadcrumb on the custom template doesn’t output anything. It does work on all other pages though.