In some cases you may encounter limitation regarding the count of menu items that you can have on your WordPress installation. This happens due to a limitation in PHP settings for some servers that can be fixed by increasing those values.

Menu Items Limit

In case of limitation in adding new menu items you will get below warning:

Menu Items Limit Warning

To do that you need to access your php.ini of the server if you have dedicated one, or ask your hosting provider if you use a shared hosting. You just need to set options below to proper values:

max_input_vars = 1000;

You can also set this value in .htaccess file by adding the line below:

php_value max_input_vars 1000

1000 is the recommended value for Artbees themes on this case.
Please consider one of main symptoms of this problem as NOT saving menu items after their addition. This can be fixed as mentioned above.

Why you can add more Items in some other themes than in Artbees themes

Both Jupiter and The Ken WordPress themes has “5” (Mega Menu, Menu Icon, Background Image, Background CSS Values, Widgetized area) more input variable for each menu items you add into your menus. Therefore you will reach to the limit much faster than let’s say a WordPress default theme.