SM-J337P First test by firmware combo its fail
 

Using Version...1.0.0.0059
Selected Model GT-I5503
Selected Task SAMSUNG SPRINT UNLOCK

Searching ADB device Please wait..
Device Detected...
SELinux := Permissive
model:= SM-J337P
Androids Version:= 8.0.0
Description Version:= j3topeltespr-user 8.0.0 R16NW FA80_J337PVPU1ARE3 release-keys
Platform:= exynos5 [ samsungexynos7885 ] [ SHANNON327 ]
Baseband:= J337PVPU1AREC
VER:= FA80_J337PVPU1ARE3/J337PVPU1AREC/FA80_J337PVPU1ARE3
Unknown CSC
EFS CSC := SPR
Knox Warranty := Not Void
AP UART Status := Enable Already.
Security Patch := 01-04-2018
Simstatus:= READY
ANDROID-ID = 520051634aae455f_0000FD9982
type1 root exploit possible.
Device is not rooted
SAMSUNG ALL SPRINT UNLOCKING STARTED...
Checking Data...
Waiting for Loader...
Loader Ok...
Type 2a
dbg1...MTVfMTJfMTBfMV80NF80Rl80RV80NV80Q180OF8xXzF fOF80NV80NF81MV80Q181NF80NV8xXzQ0XzUzXzRFXzQyXzlfM V80NV80NF81NV81M180RV80M182MF8zMw==

!!! Fail !!!!

Restart Phone Manually if not done auto...
Total Time Take...00:00:23
Log Saved

alot phones 2018 coming big security :D;)

@ghacks

Did you tried ask/rpl method? I think it should work.