Unable to Complete Logon to cTrader FIX API for Trade Execution

Hello,

I am currently integrating the cTrader FIX API with my trading system, but I am experiencing an issue where the session is created, but the logon process is never completed.

Current Setup:

• Host: demo-us-eqx-01.p.c-trader.com
• Port: 5202 (Plain text)
• SenderCompID: demo.pepperstone.5010171
• TargetCompID: CSERVER
• SenderSubID: TRADE
• Username: 5010171
• Password: *****
• FIX Version: 4.4

Observed Behavior:

1. The session is successfully created (Created session appears in logs).
2. The onLogon() function is never triggered, meaning the server does not complete authentication.
3. No rejection messages (MsgType=3 or MsgType=5) are received in fromAdmin().
4. The server does not disconnect immediately, but no further responses are received.

Troubleshooting Done:

• Ensured that TargetSubID=TRADE is explicitly set in the logon message.
• Verified credentials and FIX session settings (ResetSeqNumFlag=True, EncryptMethod=0).
• Captured all incoming server messages, but no rejection errors were found.
• Switched to a new demo account to rule out account-specific restrictions.
• Confirmed network connectivity and correct FIX message sequencing.

Questions:

1. Are there any additional requirements for a demo account to access the Trade API via FIX?
2. Should TargetSubID be set differently for trade execution?
3. Are there any known limitations or permissions required for order execution via FIX API on a demo account?
4. Is there a way to diagnose why the logon process is not completing?

I appreciate any guidance on this issue. Thank you.