Cannot leave a room

[progval]

Description

Element shows me that I'm in the room !wkyjxWeAOBpKMvHbno:matrix.org, and I even have a notification from it that I can't dismiss.
When I try to leave it I get this error: MatrixError: [403] @pinkie:matrix.org not in room !wkyjxWeAOBpKMvHbno:matrix.org. (https://matrix-client.matrix.org/_matrix/client/v3/rooms/!wkyjxWeAOBpKMvHbno%3Amatrix.org/leave)

Steps to reproduce

1. Try to leave !wkyjxWeAOBpKMvHbno:matrix.org (former Codeberg room, that got upgraded)

Homeserver

matrix.org

Synapse Version

1.121.0rc1 (b=matrix-org-hotfixes,0fb2633a27)

Installation Method

I don't know

Database

I don't know

Workers

I don't know

Platform

matrix.org

Configuration

No response

Relevant log output

I don't have any

Anything else that would be useful to know?

I initially opened this issue on Eleweb (element-hq/element-web#28479 and element-hq/element-web#28599), but they say it's a server bug.