Joomla! Template 002041 - Item Support

Hello,
I have three mistakes:
1: When I set the error reporting field to maximum in the Joomla configuration in the "Server" tab, I get the error message on the website
"Warning: A non-numeric value encountered in /www/htdocs/xxx/xxx/modules/mod_as_menu/tmpl/styles.php on line 22
Warning: A non-numeric value encountered in /www/htdocs/xxx/xxxx/modules/mod_as_menu/tmpl/styles.php on line 26"
In styles.php stands

Line 20: $font_size1 = $params->get('font_size1');
Line 21: if($font_size1)
Line 22: $line_height1 = 'line-height: ' . $font_size1 + 2 . 'px;';
Line 23:
Line 24: $font_size2 = $params->get('font_size2');
Line 25: if($font_size2)
Line 26: $line_height2 = 'line-height: ' . $font_size2 + 2 . 'px;';

What is wrong?

2: Since the Joomla update to 3.9.4 I have a problem with the main menu. In the category "Menu" the connection to the menu module is missing. I should or can only build a new module there. In the extensions, however, there is a module that is also linked to the main menu. How can I merge the menu and module again?

3: In the contact field, as in your example https://demo.astemplates.com/joomla-templates/002041/index.php, are two different fonts. How do I change this?

The URL is https://www.en-ef-de.de

For installation I have uploaded the package file.

Regards