Affected Coin: Lethean
Details: Coins not arriving at wallet when 16-hex (8 byte) payment ID is used even though valid Tx_ID is given.

Withdrawal issue had been RESOLVED by STEX.COM.

What I can say up to this point, STEX.COM is not a scam. They are here for real business, but their support team has a lot of room for improvement.

Special thanks for LETHEAN team for assisting me solving this issue.