Custom taxonomy query not working with switch_to_blog

I find the solution: Tax_query not working on multisite

(I dont say, that I work with switch_to_blog, because everything is works fine with this function… everything, including postmeta queries, category__not_in, etc., but EXCEPT: tax_query)

So, “you have to register that custom taxonomy in both blogs”. <– so the problem originate from the different themes, when in the current used theme not registered the custom taxonomy. [BUT, DONT NEED TO ADD TERMS TO THIS TAX, only register]