Custom URL is not indexed

Hi,

I have a problem with slugs on a list details page, which I can’t figure out the cause of.

I am using the SEO:Slug field to define a custom URL, as shown in the following image:

However, I can’t make the slug URL the canonical one and therefore be the URL that Google’s crawler ends up indexing.

In the Google Search Console, URLs with slugs appear as non-indexed, because they have a redirect to URLs without the slug (of type ?recordId=recNgpKPoV8VqhWJZ)

I have another site where the SEO:Slug works as expected, ie: the custom URL is the one that gets indexed.

Any idea where the problem could be?

Thank you.

Can you pls DM me a real link so I can check ?