get_terms and term_query return empty array on multisite

Hello,

We developed a multisite.

We have a custom post type called ‘products’ and a custom taxonomy called ‘producttype’. On the archive page of the custom post type, we use ‘get_terms’ to display all the ‘producttypes’. This works on all the subsites in the multisite, except the first. When we use ‘get_terms’ or even a ‘term_query’, we get an empty array as result.

I’m not sure what I’m doing wrong here, it seems multisite specific.

So it doesn’t work here: https://www.wassenburgmedical.com/products/
But it does work here: https://www.wassenburgmedical.com/uk/products/ or here:
https://www.wassenburgmedical.com/nl/producten/

Could you help me out?

Thanks in advance!
-Kevin

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