Form translation dialogues hidden behind page's modal veil

[kpu]

On booking.com when trying to use "Form translation", two text fields appear behind the grey overlay that booking.com uses to give the impression of a modal dialogue.

0. Install current extension
1. https://www.booking.com/hotel/gb/park-plaza-westminster-bridge.es.html
2. Click translate
3. Click Yes to enable translations of forms (and wait an unusually long time for "Loading form translation")
4. Click "Ask a question." lower down in the page to open a modal dialogue.
5. Click on the textarea.

[andrenatal]

Dupe of #16