Icon scaling issues with HA 2021.11

[EKCJ]

Since the 2021.11 update to HA, several users have reported that having any custom icon integration installed causes scaling issues with custom icons including the HACS icon in Firefox, e.g. https://github.com/home-assistant/frontend/issues/10556

I've confirmed for myself that after disabling fontawesome, the scaling issues are resolved. I don't have any other custom icon sets installed.

The issue is similar to https://github.com/thomasloven/hass-fontawesome/issues/50 so I tried rolling back to fontawesome v 2.1.3, but the issue persists.

The incorrectly scaled icons in this screenshot are all fontawesome ones, the mdi ones are correct: Sometimes affected icons in the views navigation bar disappear, sometimes they are huge (see 2nd picture below):

Other custom icons, such as the HACS icon and the shower icon (which I created myself by following these instructions) are also affected:

If fontawesome is disabled then the fontawesome icons stop working (obviously) and the other custom icons scale correctly.

I am using fontawesome v 2.1.4, HA docker v 2021.11.5 and Firefox v 94.0.1. Possibly related to the icon picker update in 2021.11 - I updated straight from 2021.10 to 2021.11.5.

[MJHeijster]

In my case, the font-awesome icons are too big compared to the other icons. It's a weird issue we're having in firefox.. .

[thomasloven]

Should be fixed in release 2.1.5

[MJHeijster]

I can confirm it fixed it for me. Thank you.

[Stooovie]

Problem is back after HA restart. Frontend cache in the HA app is reset, icons are still huge. I don't know why. They WERE the right size just after updating the Fontawesome addon.

[EKCJ]

The fix appears to persist through restarts for me, but I only had the original issue in firefox, not in the HA app.