SSO login fails with no session available

### Steps to reproduce

I am hosting Synapse and Nextcloud on the same server with Nextcloud providing OIDC.

1. Configure synapse in a sub-domain but present without sub-domain
2. Configure an OIDC
3. Login with SSO
4. Login to other locations with SSO - 2 maybe 3, I had 4.
5. Within the app, go to privacy -> Sessions
6. Attempt to log-out a session
7. You'll be prompted to login to verify identity, do so

* chat.\ - Points to Synapse Docker instance port 8008
* matrix-fed.\ - Points to Synapse Docker instance port 8008
* cloud.\ - Points to Nextcloud instance
* \/_matrix/ - Points to Synapse Docker instance 8008
* \/_synapse/ - Points to Synapse Docker instance 8008
* .well-known/matrix/server - directs to matrix-fed.\
* .well-known/matrix/client - directs to chat.\

This has all been done to get successful connection to the federation. And some additional back story can be found https://github.com/matrix-org/matrix.org/issues/206#issuecomment-2087876120

----

```
server_name: ""
pid_file: /data/homeserver.pid
listeners:
- port: 8008
tls: false
type: http
x_forwarded: true
resources:
- names: [client, federation]
compress: false
database:
name: sqlite3
args:
database: /data/homeserver.db
log_config: "/data/chat..log.config"
media_store_path: /data/media_store
registration_shared_secret: "this is the secret I use"
report_stats: true
macaroon_secret_key: "I have special secrets I tell you"
form_secret: "Alright I give, the secret is"
signing_key_path: "/data/chat..signing.key"
trusted_key_servers:
- server_name: ""
- server_name: "chat."

web_client_location: "https://cloud./apps/riotchat/#/home"
public_baseurl: "https://chat./"

password_config:
enabled: false

sso:
client_whitelist:
- "https://cloud."
- "https://"
- "https://chat." # Ok, I probably don't need this
update_profile_information: true

oidc_providers:
- idp_id: nextcloud
idp_name: "Secret"
skip_verification: false
issuer: "https://cloud."
client_id: "gah, now you know"
client_secret: ""
client_auth_method: "client_secret_post"
scopes: ["openid", "profile"]
authorization_endpoint: "https://cloud./apps/oidc/authorize"
token_endpoint: "https://cloud./apps/oidc/token"
userinfo_endpoint: "https://cloud./apps/oidc/userinfo"
jwks_uri: "https://cloud./apps/oidc/jwks"
```

### Outcome

#### What did you expect?

The login to be successful and verified, with the session being removed from the active list.

The initial login page should take you to chat.\

#### What happened instead?

The Initial Login Page opens \ when you go to click to login it takes you to the chat.\ and presents a page that the session is missing.

### Your phone model

Samsaugn A13

### Operating system version

Android 11

### Application version and app store

Element 1.6.14 G-310cecf5

### Homeserver

Synapse 1.105.1

### Will you send logs?

No

### Are you willing to provide a PR?

No