How to reproduce:
1. Create a new Unity project and install the Multiplayer Services package
2. Link the project to a Unity Cloud project ID in Project Settings -> Services
3. Import the attached "Repro" script and attach it to any GameObject
4. Go to Project Settings -> Player -> Other Settings and set Scripting Backend to Mono and Managed Stripping Level to Medium
5. Build and Run a Development Standalone Player with "Autoconnect Profiler" enabled
6. Set the Console to Player client and observe the logs
Expected results: The session is created, as it is with Managed Stripping Level set to Low
Actual results: "[Wire - ws#]: FATAL WebSocket.connect An error has occurred during a TLS handshake." is logged repeatedly with an increasing backoff and CreateSessionAsync never returns and never throws, so the player hangs indefinitely
Reproducible with: 2.3.1 (6000.5.9f1)
Reproducible on: Ubuntu 24.04.4 LTS, macOS Tahoe 26 (M1)
Not reproducible on: No other environment tested
Note: Stripping level matrix run on the identical project and Scene - Mono + Minimal passes, Mono + Low passes, Mono + Medium hangs, Mono + High hangs, IL2CPP + Minimal passes, IL2CPP + High passes, Linux Dedicated Server passes on both Mono and IL2CPP. Lobby REST calls (CreateLobbyAsync, QueryLobbiesAsync, DeleteLobbyAsync) all succeed in the same hung build, so only the managed WebSocket TLS path is affected. This points at managed stripping removing types the Mono WebSocket TLS stack needs, i.e. missing link.xml preservation in com.unity.services.wire (1.4.4).
There are two separable problems - the stripping breakage itself, and the fact that CreateSessionAsync retries forever with no timeout or cancellation, so a shipped game freezes instead of surfacing an error.
First lines of error:
[Wire - ws#]: [9/2/2026 11:10:11 AM] FATAL WebSocket.connect An error has occurred during a TLS handshake.
[Wire - ws#]: [9/2/2026 11:10:12 AM] FATAL WebSocket.connect An error has occurred during a TLS handshake.
[Wire - ws#]: [9/2/2026 11:10:14 AM] FATAL WebSocket.connect An error has occurred during a TLS handshake.