Hello,
We are glad that you sorted out.
Read more – https://xstore.helpscoutdocs.com/article/60-xstore-theme-requirements
The PHP Max Input Vars is the maximum number of variables your server can use for a single function. To work properly with a modern WordPress theme set this value to 3000. If the value is too low, you may experience problems such as can’t save menu settings when added a lot of items there.
Regards