BizTalk Sequential convoy odx receives duplicate messages

Question

Hello BizTalk Gurus,
My publishing odx is publishing the right number of messages. I confirmed it by creating a subscription filter in send port, and it collected the right number of messages.
In the subscriber orchestration, which is a sequential convoy, when I only enlist the odx and see the 'Show Messages' in the Admin Console, it shows duplicate messages. For example, if the publisher odx is publishing 10 messages, I see 20 messages in the subscriber orchestration message queue.
The correlation is set on BTS.MessageType.

Another strange thing I noticed that in the subscribing odx, after the second receive shape (correlated message), I put a trace to see the message count, and it shows only 10 messages are received. Not sure why then in the subscribing odx message queue in Admin Console, it is showing duplicate.

Any help will be much appreciated.