Divi Menu Repair Needed

We need the navigation menu on our bilingual (German/English) WordPress site beautycheck.ch to work flawlessly on desktop, phone and tablet. The site is built with Divi 5 (header in the Theme Builder), Polylang, Rank Math and WP Rocket.

What needs fixing:
1. Desktop mega menu: the submenu text appears about 0.3 s before its dark background, and panels stay open when moving to other items.
2. Phone: a black block flashes in the hero area while the page loads.
3. iPad: the hamburger menu does not open.
4. Phone: tapping outside the open menu does not close it.
5. Phone: after a reload, submenus are sometimes stuck open and the menu can no longer be closed (iPhone, Firefox).
6. Clean-up: one menu item wraps onto two lines, some menu links point to the wrong language, stray characters in the menu code, missing accessibility labels.

Bugs 2-5 are all in the phone/tablet popup menu. Maybe a clean rebuild is of that menu is easier that behaves like the menu on ayun.ch. The look stays the same; only the behaviour changes. If you think a targeted fix is better, tell us why.

The attached PDF brief describes each bug with screenshots, likely causes and the checks we will use for acceptance. Three screen recordings show the bugs.

Acceptance: tested on iPhone (Safari, Chrome, Firefox), Android (Chrome, Samsung Internet), iPad (portrait and landscape), and Mac and Windows browsers, on real devices or BrowserStack. The fixed price is paid once all checks pass.

Deliverables: fixes live in both languages, short screen recordings of the key tests, and notes on what was changed and why.

Please include in your bid:
- A fixed price for all six parts
- Rebuild or targeted fix for the phone/tablet menu, and why
- Your first guess at the cause of the iPad and reload bugs
- Divi 5 sites you have built or fixed (Divi 5, not only Divi 4)
- Your timeline and earliest start date

Typography, SEO and performance work are not part of this job. They are planned as follow-up projects if this one goes well.