Long-left rooms keep showing up in sidebar but without room name

[CR0CKER]

Description

Old rooms that have long been left keep showing up in the sidebar, and content can be seen as if I have never left them, but the rooms don't have any address and no name, just a list of usernames in them. See screenshots. This happens across devices, including Element iOS.

Steps to reproduce

I have no idea how to reproduce this issue and have not seen this bug reported elsewhere. This has been happening repeatedly over many month and many releases. the rooms disappear after I do a cache refresh of the app via preference settings.

Version information

• Platform: desktop

For the desktop app:

• OS: macOS
• Version: 1.7.32

[SimonBrandner]

This happens across devices, including Element iOS.

Perhaps this is a homeserver thing?

[t3chguy]

Yup this is most likely a synapse bug.

[CR0CKER]

The account under which this is happening is on matrix.org, so I'm assuming it's happening under the most recent Synapse version.

[t3chguy]

Could be specific to the worker mode configuration that matrix.org is running, they also occasionally run newer than release code or modifications thereof

[aaronraimist]

Are these version 1 rooms? Go to the advanced section of the room settings to check. If they are then it is probably a state reset.

Related: #8246

[CR0CKER]

Yes, they are all version 1 rooms:
!svJUttHBtRMdXmEhEy:matrix.org
!uDQoIebqsjEEtmWLrO:disroot.org
!OGEhHVWSdvArJzumhm:matrix.org