bug? command_status field (%A) missing in DLR of split messages

Hello,
I think we are experiencing a bug in kannel (1.4.4) that does not include
command_status details in the DLR url for long messages that were split.
See the excerpt of the debug log below.

2018-04-11 19:00:38 [30573] [6] ERROR: SMPP[xxxx]: SMSC returned error code
0x0000000b (Invalid Destination Address) in response to submit_sm PDU.
2018-04-11 19:00:38 [30573] [6] DEBUG: Set split msg status to 3
2018-04-11 19:00:38 [30573] [6] DEBUG: Parts of concatenated message failed.
2018-04-11 19:00:38 [30573] [6] DEBUG: SMSC[xxxx]: creating DLR message
2018-04-11 19:00:38 [30573] [6] DEBUG: SMSC[xxxx]: DLR =
https://myurl/api/dlr?status=%d&code=%A&id=123456&dt=%t

Normally for rejected messages the value of the %A parameter is something
like:

NACK/0x0000000b/Invalid Destination Address

However, when the original MT message is a long message that gets split,
the %A parameter in the DLR url looks like this:

NACK/

Is this a known issue? Is there a fix for this?

Thanks,
Jeff Thorn