Environment:
Browser / Version: Firefox Nightly 97.0a1 (🦎 97.0a1-20211221093038)
Operating System: Google Pixel 5 (Android 12) - 1080 x 2340 pixels, 19.5:9 ratio (~432 ppi density), Samsung Galaxy S8 (Android 9) - 1440 x 2960 pixels, 18.5:9 ratio (~570 ppi density)

Prerequisites:
ETP - Strict enabled.

Steps to reproduce:

1. Navigate to https://www.saloncentric.com/deals?prefn1=dimBrand&prefv1=Sam%20Villa
2. Tap "Search" button.
3. Observe behavior.

Expected Behavior:
"Search" is triggered.

Actual Behavior:
Nothing happens, "Search" button is not functional.

Notes:

1. The issue is also reproducible for "Browse" menu and "Account" button and the top options bar overlaps top part of the sites (and can't be scrolled).
2. The issue is not reproducible with ETP - Standard.
3. Screenshot attached.

I see this in the console:

Uncaught TypeError: can't access property "length", o is undefined
    RICHRELEVANCE https://www.saloncentric.com/on/demandware.static/Sites-saloncentric-us-Site/-/en_US/v1651207256834

So this is related to Rich Relevance. Our shim is treating the value RR.data.JSON incorrectly, as the site expects there to be an array RR.data.JSON.placements, and the site's search works fine if we make that an empty array. So it's worth doing that.

https://hg.mozilla.org/mozilla-central/rev/5579801f7ed2