Cannot log in using companion app or IronFox

[Ghoelian]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in safe mode to rule out problems with unsupported custom resources.

Describe the issue you are experiencing

When trying to log in to my Home Assistant instance using the companion app (minimal version), or using IronFox with all extensions disabled, it fails with nothing but a "Start over" button, and a notification in Home Assistant: "Login attempt or request with invalid authentication".

When I use Vanadium (GrapheneOS's Chromium fork), I can log in just fine. It also works in a private tab in IronFox.

I'm using a password manager so I am 100% sure I'm using the same username/password.

Describe the behavior you expected

The log in to succeed, or fail with a meaningful error.

Steps to reproduce the issue

1. Install home assistant companion app from github release
2. Log in

What version of Home Assistant Core has the issue?

2025.11.1

What was the last working version of Home Assistant Core?

No response

In which browser are you experiencing the issue?

IronFox v145.0 build #2016125650, also official companion app

Which operating system are you using to run this browser?

GrapheneOS build 2025110801

State of relevant entities

Problem-relevant frontend configuration

JavaScript errors shown in your browser console/inspector

I'll have to connect a debugger to my phone, will add later.

Additional information