I’m using Polylang on my website and it looks good on the laptop but on the mobile there is an extra green box next to the flags and the menu is placed wrong.
Please note that the Hotel Booking plugin is not fully compatible with Polylang, so we recommend using WPML, as it is 100%-compatible with the Hotel Booking. As for your issue, it appears to be a styling one. Provide me with the URL to the page in question, so I take a closer look at it.