"Requested DTC Status" result is intermittent

[numlauf]

when using "Verify DTC Channels" in j1939 custom device

we

1. set the "Expected DTC" channel to spn.fmi we are looking for
2. set "Diagnostic Command" to 1 (get all j1939 devices address)

our Device under test(DUT) responds with the DM1 and DM2 messages EVERY TIME

3. set "Diagnostic Command" to 2 (Verify DTC)

"Requested DTC Status" channel returns a 0, 1, or 2 corresponding to what our DUT responds with.

sometimes, about 3% of the times even though our DUT responds with a valid DM1 and DM2 messages
The "Requested DTC Status" value is Wrong

not sure if the intermittent incorect value from the custom device is a timing issue.

our PXI target rate is 1000HZ
our DUT responds to dm1 request from custom device in about 3-6 ms
our DUT responds to dm2 request from custom device in about 10-60 ms
our can card is pxie-8510

we also noticed that "diagnostic command status" is not updating.
the "diagnostic Error code" we Always get even when functioning properly is 074384374

we can proved can trace if needed ?