After the January 2026 Samsung update, several U.S. Samsung devices that were previously unlocked using the SIMUnlocker relock / limited country method have become network locked again after updating.
We’ve seen this mainly on newer U/U1 models.
Typical symptoms:
Network Locked / Phone Locked after OTA update
In some cases device asks for MCK code, even on carriers that normally don’t require one
Reported / tested models:
S25 series – SM-S938U, SM-S937U, SM-S936U, SM-S931U
S24 series – SM-S928U, SM-S926U, SM-S921U
Fold 6 – SM-F956U
Flip 6 – SM-F741U
Working fix:
Relock can usually be fixed by flashing an older CP (modem) from firmware with the same BIT version using Odin. Flashing a lower BIT will not work.
Side effect (important):
Because CP version no longer matches the rest of the firmware, Samsung OTA updates normally stop working, which helps prevent the relock from happening again.
For additional protection, Samsung system updates can also be disabled manually via ADB:
adb shell cmd package disable-user --user 0 com.wssyncmldm
adb shell cmd package uninstall --user 0 com.sec.android.soagent
This update-block method can be used in general as well, not only for this specific relock issue.
If the phone updates to a higher BIT version, this fix will no longer be possible.
Full explanation + demo video (CP flash + update block):
Posting this for anyone affected by the recent relock after OTA.
We’ve seen this mainly on newer U/U1 models.
Typical symptoms:
Network Locked / Phone Locked after OTA update
In some cases device asks for MCK code, even on carriers that normally don’t require one
Reported / tested models:
S25 series – SM-S938U, SM-S937U, SM-S936U, SM-S931U
S24 series – SM-S928U, SM-S926U, SM-S921U
Fold 6 – SM-F956U
Flip 6 – SM-F741U
Working fix:
Relock can usually be fixed by flashing an older CP (modem) from firmware with the same BIT version using Odin. Flashing a lower BIT will not work.
Side effect (important):
Because CP version no longer matches the rest of the firmware, Samsung OTA updates normally stop working, which helps prevent the relock from happening again.
For additional protection, Samsung system updates can also be disabled manually via ADB:
adb shell cmd package disable-user --user 0 com.wssyncmldm
adb shell cmd package uninstall --user 0 com.sec.android.soagent
This update-block method can be used in general as well, not only for this specific relock issue.
If the phone updates to a higher BIT version, this fix will no longer be possible.Full explanation + demo video (CP flash + update block):
Posting this for anyone affected by the recent relock after OTA.