[BUG] - SDP/ICE Failure when connecting during Endpoint ID Change

[StomyPX]

**UE Version: **
UE 5.3

**Frontend Version: **
UE5.3

Problem component
Signalling Server/Frontend

Description
If a player attempts to subscribe to a streamer immediately after they've connected, the SDP/ICE negotiation may lock up requiring a refresh

Steps to Reproduce:

1. Launch signalling server
2. Launch packaged UE project
3. Open tab to PixelStreaming URL.
4. Count to 3
5. Click to begin streaming

The timing has to be just right (roughly 2-3 seconds) but if you can get the player to connect immediately after the streamer connects, you can catch it at the point where it still has __LEGACY__ as its endpoint ID. This causes SDP/ICE negotiation to be initiated with the wrong endpoint ID and requires refreshing the page to connect again properly

Expected behavior
Ideally the signalling server could communicate the id change to the frontend and complete or restart the negotiation process without the user having to know. Or the endpoint ID could be passed as part of initially connecting the streamer to the signalling server and so not require any handling at all.

Platform (please complete the following information):

• OS: Manjaro Linux
• Browser: Google Chrome 115.0.5790.170