Why is my Ella theme header nav not displaying correctly after update?

I’m currently updating my Ella theme to the 6.5 version and the header nav - plain is not working properly: is showing the wrong main many and doesn’t show the sub categories (is blank). When I refresh my website the head nav works properly for 1-2 seconds (correct main many and sub categories) but then it changes.

Anyone know how to fix this problem? That’s the only reason why I can’t activate the new theme version.

Hope someone can help me

@JessicaCok

Please share your store URL!

Thanks!