var contentLink = _referenceConverter.GetContentLink(code);
When I try to find a product via code the contentreference becomes empty.
This works on several other products and I can not see any difference between the products that work and those whom doesn't work.
Any ideas how to debug this further?
Can you check if a product with that code actually exists?
Yes it does, if only it was that easy.
Did you make sure the code you passed matches exactly with the code in database? Did you try the other overload which takes the catalog content type?
Exactly as in database, yes. Overload with catalog content type, yes - same result.
As written before.
Then you should probably contact developer support service for further assistance :)