Oh, in that case can you go to /admin/site_settings/category/branding?filter=manifest%20icon and upload a new 512x512 PNG in there?
After that try re-adding the site to the homescreen on Firefox Android.
Oh, in that case can you go to /admin/site_settings/category/branding?filter=manifest%20icon and upload a new 512x512 PNG in there?
After that try re-adding the site to the homescreen on Firefox Android.