Authorization server discovery breaks app UI

### Steps to reproduce

For context, I've been using Element X on android for a couple of months without major issues, in combination with my own synapse and matrix authentication service. MAS itself uses an external OIDC provider, if that matters.

1. Where are you starting? What can you see?

The problem occurs right away when starting the app.

I think Element X was recently upgraded but I'm not sure, it's at `25.09.1`. The server has not had any changes recently.

### Outcome

#### What did you expect?

Element X to load normally and show new messages.

It's of course possible there's a real problem with the server, I'll be looking into server logs. But at the very least the UI shouldn't shake like this under any circumstances.

#### What happened instead?

There is an error message:
> An error occurred, you may not receive notifications for new messages. Please troubleshoot notifications from the settings.
> Reason: authorization server discovery failed: OAuth 2.0 is not supported by the homeserver.

Additionally, new messages are not shown -- I see older messages but not newer ones which I can see using another client (element web).

Additionally, most of the UI in the main screen -- everything except the error message and the big "plus" button in the bottom -- is shaking vertically, like the UI is changing multiple times per second in a loop.

I can enter the notification settings as advised and run the notification tests, which all pass -- I use unifiedpush with ntfy.

I also entered the encryption settings, and the "Allow key storage" button and label also have the vertical shaking like the main screen.

### Your phone model

Fairphone 3

### Operating system version

Android 9

### Application version and app store

Element X 25.09.1

### Homeserver

Synapse 1.121.1

### Will you send logs?

Yes

### Are you willing to provide a PR?

No