Menu flickering problem

Menus which have submenu, when we click on submenu,it flickers so much that submenu is not opened.
we can't place cursor on submenu items.
Link is : www.trendzacademy.com
What is the problem? Please have a look at the link.

Items are too condensed. In template options in "Menu config" for that menu set item height or vertical padding bigger

Hello there,
I have tried increase the height of the menu and submenu and the padding but still sometimes when I am loading the page the submenu menu is flickering. Any suggestions of what to change exactly?
Thank you in advanced.

Send link so we have an look

When I will publish it I will send you the link. Thank you!