Hello all, my name is Ricarda and I am not sure whether I am 'right' here with my issue...Please forward or delete my post, if unsuitable.

I am using the theme sydney. And lately I chose 'brave' as my internet browser. Unfortunatly the sub menues of my web page are not accessible. Can anybody of you advice me?
My tech support told me it depends on the programming of the theme? Is this correct?
Thank you