Add-on web UIs do not load in Firefox

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1

I use Firefox (on Arch Linux) quite a bit. I have a couple Home Assistant add-ons that have their own web UIs (Studio Code Server, Node-Red).

When I open my Home Assistant interface in Firefox I cannot access the web UIs for these add-ons. I have links for the add-ons checked to “Show in sidebar”. I can see the icons for the add-ons in the sidebar, but when I click them I just get a page with the sidebar and nothing else. The same thing happens if I navigate to that add-on in (Settings->Add-ons->Studio Code Server->click on “Open webUI”).

When I access Home Assistant in Brave or Chrome, everything seems to behave as expected. I click an add-on’s link in the sidebar and that add-on’s web UI loads up. I also get to the add-on’s web UI by navigating the series described above.

2

Just to add I’m also experiencing this as of the last couple of days.
So much so that I ended up de-coupling HA from Zigbee2MQTT and MQTT server, just so I could access them (as an aside, this seems to have been a good move anyway).

Current addons I have installed, all experiencing this issue, are Node-Red, Terminal, and VScode.

Does seem to be only with Firefox. Chrome works fine (not tested any other browsers yet).

As there seems to be very little recognition of this issue yet I will do my own digging and report back if I find any resolution. Again this has all been working fine until a couple of days ago. First point of investigation is any Firefox updates.