unlock j737a not done

i try to unlock j737a binary 2 via server.
first, phone has frp, so i flash combination. then flash
to stock without flash modem n userdata, hidden
then i unlock

log:

Checking Login and Password... OK
Ballance: 25 crd.
You have 25 credit(s) left. This operation takes 10 credits.Continue? No
Operation: Unlock
Selected model: SM-J737A
Software version: 34.5

Checking Login and Password... OK
Ballance: 25 crd.
You have 25 credit(s) left. This operation takes 10 credits.Continue? Yes
Waiting ADB device... OK
Reading phone info...
Model: SM-J737A
Android version: 8.0.0
PDA version: J737AUCS2ARH1
CSC version: J737AATT2ARH1
Phone version: J737AUCS2ARH1
Product code: SM2J737AZKAATT
CSC country code: USA
CSC sales code: ATT
Phone SN: R58KA3X3V6F
IMEI: 354807092094655
HW version: REV1.0
RF cal date: 20181017
Chip name: EXYNOS7870
Modem board: SHANNON315
Security patch: 2018-08-01
Boot Warranty bit: 0
SIM State: NETWORK_LOCKED
Initialization zTool... OK
Running zTool, please wait... OK
Reading data from phone... OK
Searching server... OK
Checking server answer... OK
Executing... OK
Reading data from phone... OK
Calculating... OK
Searching server... OK
Waiting for server answer...
Incorrect size of server answer

Operation: Unlock
Selected model: SM-J737A
Software version: 34.5

Checking Login and Password... OK
Ballance: 15 crd.
You have 15 credit(s) left. This operation takes 10 credits.Continue? No


credit already cut, but phone still locked.

please help abaout this problem.
thanks