Category slug in menu remaines untranslated or WP Engine issue

Hi,

we have product category links in menu, but somehow, there is a hybrid (English-Czech link) happening in the menu, which doesn’t work.

Read the issue here on WP Engine support, I would be more than glad to assist and solve it as soon as possible:
https://help.wpengine.com/hc/en-us/requests/880499?page=1