Hello,
You are using Elementor and WPBakery, it would be better to select only one editor, to prevent conflicts.
1/ Removed from custom CSS code
2/ Appearance > Menus. For example, this menu https://prnt.sc/XS9GD_25TB5U was created using a static block https://prnt.sc/23e2UKYFE8e6 Go to Elementor >Settings > post types > enable Elementor for static blocks, then go to Static blocks and edit “Mega menu 06 – Accessories niche-market02” using elementor. You can create own static blocks, and select them for menu items with Mega menu types https://prnt.sc/XkN8xaiou5xZ
Regards