UCP/FaxPro reports "Unknown error (Originate failed)" on Busy

When sending to a Busy number, the system retries the correct number of times and with the correct delay, but ends up reporting in the "Failed" folder "Unknown error (Originate failed)".

This tells users that there was an error and makes them think there is a problem with their phone/fax system.  Really, the problem is that the receiver's number is Busy.

The logs clearly indicate the number is Busy:

VERBOSE[10862][C-000236a4] app_dial.c: Called SIP/siphost/1234567890
VERBOSE[11940][C-000236a4] chan_sip.c: Got SIP response 486 "Busy here" back from 64.7.163.60:5060
VERBOSE[10862][C-000236a4] app_dial.c: SIP/siphost-0004bc6b is busy
VERBOSE[10862][C-000236a4] app_dial.c: Everyone is busy/congested at this time (1:1/0/0)
VERBOSE[10862][C-000236a4] pbx.c: Executing [s@macro-dialout-trunk:25] NoOp("Local/1234567890@from-internal-0000cd68;2", "Dial failed for some reason with DIALSTATUS = BUSY and HANGUPCAUSE = 17") in new stack
VERBOSE[10862][C-000236a4] pbx.c: Executing [s@macro-dialout-trunk:26] GotoIf("Local/1234567890@from-internal-0000cd68;2", "0?continue,1:s-BUSY,1") in new stack
VERBOSE[10862][C-000236a4] pbx_builtins.c: Goto (macro-dialout-trunk,s-BUSY,1)
VERBOSE[10862][C-000236a4] pbx.c: Executing [s-BUSY@macro-dialout-trunk:1] NoOp("Local/1234567890@from-internal-0000cd68;2", "Dial failed due to trunk reporting BUSY - giving up") in new stack
VERBOSE[10862][C-000236a4] pbx.c: Executing [s-BUSY@macro-dialout-trunk:2] PlayTones("Local/1234567890@from-internal-0000cd68;2", "busy") in new stack
VERBOSE[10862][C-000236a4] pbx.c: Executing [s-BUSY@macro-dialout-trunk:3] Busy("Local/1234567890@from-internal-0000cd68;2", "20") in new stack
VERBOSE[10862][C-000236a4] app_macro.c: Spawn extension (macro-dialout-trunk, s-BUSY, 3) exited non-zero on 'Local/1234567890@from-internal-0000cd68;2' in macro 'dialout-trunk'
VERBOSE[10862][C-000236a4] pbx.c: Spawn extension (outbound-allroutes, 1234567890, 6) exited non-zero on 'Local/1234567890@from-internal-0000cd68;2'

It is highly preferable that FaxPro would report to end users that the Fax Failed because a Busy Signal was received.  "Unknown error (Originate failed)" is confusing. I have confirmed that this is a problem in both FreePBX 13 and 14.  Thank you.