My guess is if you hook up an ISDN Trend tester or similar in TE mode and send a call into the system it will work correctly.
Some IAD or ATA adapters have options to remove the "friendly name" etc so this will need to be fixed by AT&T in their IAD.

An example of a call from 0299998888 calling an ISDN DID 0299998000 to CIX100 PABX



15:11;36'62 S:RR
00 01 01 01
15:11;36'63 R:RR
02 01 01 01
15:11;36'64 S:RR
02 01 01 01
15:11;36'64 R:RR
00 01 01 01
15:11;40'93 R:SABME
02 01 7F
15:11;40'94 S:UA
02 01 73
15:11;40'98 R:I
SETUP(0001)
02 01 00 00 08 02 00 01 05
A1 04 03 80 90 A3 18 03 A9 83 81 6C 0B 80 30 32 |...........l..02
39 39 39 39 38 38 38 38 70 0B 80 30 32 38 36 30 |99998888p..02999
38 31 31 33 35 |98000
15:11;40'99 U:L3_MSG
15:11;40'99 S:RR
02 01 01 02
15:11;41'26 D:L3_BSY_ON
15:11;41'32 D:L3_MSG
15:11;41'33 S:I
CALL PROC(0001)
00 01 00 02 08 02 80 01 02
18 03 A9 83 81 |.....
15:11;41'36 D:L3_MSG
15:11;41'36 S:I
ALERT(0001)
00 01 02 02 08 02 80 01 01
1E 02 81 88 |....
15:11;41'54 R:RR
00 01 01 04
15:11;45'44 D:L3_MSG
15:11;45'44 S:I
CONN(0001)
00 01 04 02 08 02 80 01 07
1E 02 81 82 |....
15:11;45'48 R:I
CONN ACK(0001)
02 01 02 06 08 02 00 01 0F
15:11;45'49 U:L3_MSG
15:11;45'49 S:RR
02 01 01 04
15:11;52'28 R:I
DISC(0001)
02 01 04 06 08 02 00 01 45
08 02 82 90 |....
15:11;52'29 U:L3_MSG
15:11;52'29 S:RR
02 01 01 06
15:11;52'44 D:L3_MSG
15:11;52'45 S:I
REL(0001)
00 01 06 06 08 02 80 01 4D
15:11;52'48 R:I
REL COMP(0001)
02 01 06 08 08 02 00 01 5A
08 02 82 9F |....
15:11;52'48 U:L3_MSG
15:11;52'49 S:RR
02 01 01 08
15:11;52'63 D:L3_BSY_OFF
15:12;02'48 S:RR
00 01 01 09
15:12;02'48 R:RR
00 01 01 09

Regards
Carl