To begin we should test to see if there is a plugin conflict.
Disable Ezoic Leap and any other optimization or cache plugins.
Clear the browser caches an retest the site.
Does the menu dropdown work?
If yes, then we know its one of those plugins.
And you can re-enable them one by one to see which is causing the issue.
Then it will require “tinkering” with its settings or asking advice of the plugin author.
If No, then leave those plugins disabled.
And send us a link so we can take a closer look.