Looking for MERN stack expert who can help me — 3

We use WordPress for our website. We have added custom CSS to improve the theme’s appearance, including the navigation menu. However, the “submenu” dropdowns do not work correctly on Safari and Internet Explorer. Please see the attached photos.

We need someone who is well versed in CSS and compatibility across browsers to help. The goal is to make the navigation “navigable” no matter what browser is used.