Duplicate concurrent calls initiated after a concluded 1-to-1 call that had a third participant added.

Steps to reproduce
Initiate a 1-to-1 call with another user.

Add a third participant to the ongoing call, making it a group call.

Successfully conduct and then conclude the group call.

Navigate to any user's chat and attempt to start a new 1-to-1 call.

Observe that two identical call sessions are initiated simultaneously for the same target user.

Expected behaviour
A single call session should be initiated when starting a new 1-to-1 call.

Actual behaviour
Two concurrent call sessions are created for the same user. These sessions compete with each other, preventing proper access to recording devices (microphone/camera) as they attempt to attach to both calls. The signaling server shows two active sessions for the initiating user for the same intended call.

Talk app
Talk app version: 22.0.8

Custom Signaling server configured: yes

Custom TURN server configured: yes

Custom STUN server configured: yes

Browser
Microphone available: yes

Camera available: yes

Operating system: (e.g., Windows/Mac)

Browser name: (e.g., Firefox/Chrome)

Browser version: (e.g., 124/125)

Browser log

``` Insert your browser log here, this could for example include: a) The javascript console log b) The network log c) ... ```

Server configuration Nextcloud Version: Nextcloud Hub 25 Autumn (32.0.3)

List of activated apps:

``` If you have access to your command line run e.g.: sudo -u www-data php occ app:list from within your server installation folder ```

Nextcloud configuration:

``` If you have access to your command line run e.g.: sudo -u www-data php occ config:list system from within your Nextcloud installation folder ```

Server log (data/nextcloud.log)

``` Insert your server log here ```

Additional Notes:

The issue is reproducible both from web browsers and desktop/mobile client applications.

The core problem appears to be that call session state or cleanup is not handled correctly after concluding a specific sequence of calls (1-to-1 -> converted to group -> ended), leading to duplicate session creation on the next call attempt.

This results in a broken user experience where media devices cannot be acquired, effectively blocking any new calls until the duplicate sessions timeout or the page/client is restarted.

Reproduce the sequence of a 1-to-1 call becoming a group call, ending, and then starting another 1-to-1 call in the web or client application. Trace call-session state and cleanup around the transition, and verify that the next attempt creates one signaling session and can acquire the microphone and camera.