Galaxy J700F 6.0.1 FRP Unlock: Filed By Z3X : Firmware Problem!!

hi guys i’m new user in here (Forum)

i have Galaxy J7 2016 – J700F/DS
Have FRP Lock Google Security Lock On Android 6.0.1

The Problem is : By Mystic i do update this phone to 6.0.1
exactly: J700FXXU3BPJ1_J700FOJV3BPJ2_J700FXXU3BPJ1

Now if i want to downgrade it to any older (baseband) i get stock on Recovery mode ,Binary Problem :confused:

For Example :
Now my J7 On 6.0.1 baseband J700FXXU3BPJ1
Downgrade To 5.1.1 baseband J700FXXU1AOFJ

i wish if u get it guys sorry about my English