The <accept /> and <retract /> stanzas are not sent in Muji Call

[edhelas]

1. In a group chat Dino is never sending the <accept /> Call Invites stanza when accepting a Muji invitation.
   See https://xmpp.org/extensions/xep-0482.html#sect-idm46174443489616
2. When initiating a call Dino is never sending the <retract /> Call Invites stanza when closing a call with no participants.
3. The <presence type="unavailable"/> is not sent in the Muji MUC when leaving a call, only <left />, I expect both

This prevent me to properly follow the Muji call participants in Movim.
I do receive the <presence><muji><preparing /></muji></presence> in the Muji chatroom.