homeserver auto detection broken with Bitwarden

### Steps to reproduce

When using bitwarden to auto fill the credentials, both fields are inputted at the same time and the login field stays on focus.

### Outcome

Clicking next directly results in a login error and seems to go to matrix.org instead.

It seems like detection of the homeserver from the server part of the mxid happens only when switching to the password field, which doesn't happen in this case.

### Your phone model

Google Pixel 4a

### Operating system version

Android 13

### Application version and app store

1.7.34

### Homeserver

_No response_

### Will you send logs?

No

### Are you willing to provide a PR?

No