Parts of the UI isn’t loading in Firefox desktop for me, such as Supervisor, AdGuard Home, deCONZ.
Other pages are work fine such as Overview, Map, Developer Tools.
It’s working fine in MS Edge and the HA app, seems like the entrypoint js files has different names there.
Error example from console:
GET https://****/api/hassio/app/frontend_latest/entrypoint.4fa1b377.js
[HTTP/1.1 404 Not Found 22ms]
Uncaught (in promise) TypeError: error loading dynamically imported module
HA supervisor version: 247
FF version: 81.0.2