Snell protocol with obfs=tls + udp-relay=true causes Telegram media upload to hang indefinitely

[ychen810811]

Bug:

Snell protocol with obfs=tls + udp-relay=true causes Telegram media upload to hang indefinitely.

Repro:

• Server: Snell v3 with obfs = tls, UDP relay enabled
• Client config: snell, host, port, psk=xxx, version=3, udp-relay=true, obfs=tls
• Send photo in Telegram → infinite spinner

Workaround:

Set udp-relay=false on the Snell proxy entry; with udp-policy-not-supported-behaviour = REJECT, Telegram falls back to TCP.

Confirmed working with same Snell server on:

• Surge (macOS) with identical config
• Clash for Android with equivalent config

[ychen810811]

My previous test is problematic. Setting up relay to false doesn't work now. Will test more combinations and comment if any.