Hi dear, I faced the same issue 6 month back. I bought the device from UAE and once I was in India I reset my device with an Indian sim card inserted. After that device stopped giving updates. Once I reset my device again with a UAE sim card and the device received the update.
In your case you have 2 option. Either to reset your device with a sim card of the device origin, or flash the device with latest firmware. Flashing the CSC won't work. If you plan to flash firmware flash it with all the combination files required(CP, AP, CSC, MODEM) OTHERWISE YOU WON'T RECEIVE FUTURE OTA UPDATES.
You can search for the firmware in sammobile.
Please note that you have to update the device using smart switch application from the PC, if the issue still and the device under the Gulf region, please remove your sim card and insert gulf SIM card only and rest the device and try to update it again.