Primary Category won’t display in Breadcrumbs

I can’t get Yoast SEO breadcrumbs to display the Primary selected product category on products that have more than one main (top level) category and no child categories.

Example:
This product “Kapsel type 4 (test)” (https://zinkshoppen.dk/vare/kapsel-type-4-test/) has got two main categories and no child categories.

Product categories assigned:
1. Kapsel (https://zinkshoppen.dk/produkt-kategori/kapsel/) PRIMARY
2. Metalprofiler (https://zinkshoppen.dk/produkt-kategori/metalprofiler/)

And the first category “Kapsel” is selected as the primary category, however Yoast breadcrumbs somehow seems to disregard this and just displays the second main category “Metalprofiler” in any breadcrumb – why?

I have tried almost everything, but found no solution.

Am I doing something wrong, does Yoast not support this or is there a fix?

Thanks in advance
Ronni

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It works fine with child categories.
If there is only one main category and one selected child category, then I can mark the child category as primary and it displays fine in the breadcrumbs. It just doesn’t work that way, when it’s two main categories being selected and there’s no child categories.

I have followed the Yoast guides from A-Z, tried deactivating everything, using a default theme etc. – but the result is the same. I can’t get it to work with multiple main categories and no child categories.

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