Why are two J1939-TP messages with the same source address not transmitting simultaneously?

[Jo3932]

Unable to gateway two J1939-TP messages of same source address from one channel to another at the same time

I was trying to gateway two J1939-TP messages which have the same source address from channel 1 to channel 2. Message 1 is a diagnostic message, and both message have the same priority and periodicity. But when I was reading the data on channel 2, I found that only one message was transmitting at once and if I disable either one of them the other message has no problem transmitting. Please help me find the cause of this issue

[ZYOng]

What are the IDs for both J1939 frames?

Which XNET session did you use to transmit the message?

[Jo3932]

The first message is EC1 with PGN 65251 (0x00FEE3) and the second message is DM1 with PGN  65226 (0x00FECA). the priority bits and source address for both messages are the same, however DM1 message has the highest priority and it will continue to transmit.

I am using CANoe to transmit the message

[ZYOng]

This is a forum for NI products. If you are using CANoe, you should contact Vector instead.