Description

This is a comment based on the change introduced in matrix-org/matrix-react-sdk#2547.

Steps to reproduce

• Go to https://riot.im/develop/#/login
• Type a mxid with a non-matrix.org HS in the login box (blindly not reading the rest of the page 😉 )
• Type your password in
• It breaks.

The great thing that .well-known added was that the user had to follow one set of instructions irrespective of what default HS Riot was configured with (i.e. using riot.im or chat.openastronomy.org etc), they just typed their mxid and password in.

After this change if you are not using the default HS then you now have to click custom.

I would suggest that if you type a mxid into the username box with a domain part not matching the default that Riot is configured to it automatically swaps to the "Custom" option and does a .well-known lookup.