Room name list gets out of sync

[madduck]

Just noticed that messages by one user weren't arriving on IRC, while they showed up in riot.im alright:

Compare this to

< madduck> wtf?
< Levans> 51.0
< Levans> linux

Meanwhile, on stderr of the synapse process, I see this:

WARN Sender not in room, room: !cURbafjkfsMDVwdRDQ:matrix.org, sender: @FacyMcFace:matrix.org
WARN Sender not in room, room: !cURbafjkfsMDVwdRDQ:matrix.org, sender: @FacyMcFace:matrix.org

As you'd suspect, Riot has the user online, but s/he does not show up in /names.

So at some point, the names list got out of sync. This happens quite regularly, though I don't have any additional information (like correlations of events etc.) yet.

[madduck]

This regularly causes me to miss messages if I rely on matrix-ircd, which I hence cannot anymore. I'd say this is serious…

[madduck]

Any ideas or plans to fix this?