A week in Matrix

A user inadvertently writes in a Matrix space, causing all members of that space to receive a notification. Spaces are regular rooms, but old clients render them as regular chat rooms, causing confusion. The user manages to display the space as a regular room to inspect its settings, adjust permissions to disallow chatting, and prevent further notifications.

However, someone on a moderation list banned the user's domain, causing further issues. The user joins the policy room containing ban messages to identify the source of the ban, which takes around 40 minutes to resolve. The ban list cannot be easily overridden, requiring the user to unsubscribe from the entire list, potentially exposing the community to spam.

A few weeks later, the user still struggles with being banned and cannot see a room despite being suggested for the space. The issue persists even after the room is manually joined, re-added, or tombstoned. The problem is resolved when an admin joins the room, but it disappears again once the admin leaves. After server maintenance, Draupnir stops responding to admin commands due to an outbound federation problem with its homeserver.

Dendrite's default configuration drops all egress IPv6 traffic, which is not a good practice. The issue took over a month to debug, leaving the community space unprotected from a moderation bot.