Notes on SSO logins and media_repository worker

changelog.d/8701.doc

@@ -0,0 +1 @@
+Notes on SSO logins and media_repository worker.

docs/workers.md

@@ -262,6 +262,9 @@ using):
 Note that a HTTP listener with `client` and `federation` resources must be
 configured in the `worker_listeners` option in the worker config.
 
+Ensure that all SSO logins go to a single process (usually the main process). 
+For multiple workers not handling the SSO endpoints properly, see
+[#7530](https://github.com/matrix-org/synapse/issues/7530).
 
 #### Load balancing
 
@@ -408,6 +411,8 @@ and you must configure a single instance to run the background tasks, e.g.:
     media_instance_running_background_jobs: "media-repository-1"
 ```
 
+Note that if a reverse proxy is used , then `/_matrix/media/` must be routed for both inbound client and federation requests (if they are handled separately).
+
 ### `synapse.app.user_dir`
 
 Handles searches in the user directory. It can handle REST endpoints matching