Jitsi-meet-electron and prosody misconfiguration?

After following the quick install, I’ve had a running Jitsi Meet server for a couple of months. Works great via the web. However, I think I managed to bollox up something with prosody initially, so that it doesn’t work with the jitsi-meet-electron client.

On the dedicated machine «jitsi.domain.tld» I used:

prosodyctl register «username» «jitsi.domain.tld» «password»

When I login through the web it asks for a username in the form «username@domain.tld» but only works when I provide «username» without any “@...”. (I’ve tried both «username@domain.tld» and «username@jitsi.domain.tld»` and both fail, but since the username alone has been working, I haven’t been too sussed about it.)

However, with the jitsi-meet-electron application, configured with a username that picks up my gravatar, (ubuntourist) and email «username@domain.tld» (sans «jitsi.» because it asked for an e-mail address), and a server url https://«jitsi.domain.tld», it connects to the server, but fails with every variation on «username», «username@jitsi.domain.tld», «username@domain.tld».

(The API is aliased in nginx, etc., etc.)

Rather than bollox it up further, I may just give up on the electron app and continue going through a web browser, but if the fix is something obvious and simple, I’ll give it a go.