Already solved this. Made a syntax error before.
Thank you.
Oops, my bad: syntax error.
Hello again guys.
I figured out that the plugin is conflicting with Post Types Order plugin.
When I’ve disabled Post Types Order plugin, main nav returned back.
UPD: To be more specific Auto Sort option ruins main menu:
If checked, the plug-in will automatically update the wp-queries to use the new order (No code update is necessarily).
Hello.
Same issue here, SmartShop Lite theme.