[Q] flashing Stock UK BTU though on boot polish language shown topic

Ages ago because i was impatientto update my phone so i flashed the Polish Stock using Odin, since then i have used Odin to flash the UK Stock, though when i wipe and reset the phone it still initially comes up with the polish language, (not a massive issue i know but i want to get UK OTA if it ever comes) also if i go to sell the phone at the end of this year when the Note5 is out im sure the new owner would want to turn it on and see english.

Ive tried
Clearing the EFS cache and resetting the phone from recovery before and after flashing BTU
I made sure reactivation lock was off as I wondered if that would cause an issue though that hasn't helped. does anyone have any other ideas?

Im un-routed as i sometimes use my phone to test out corporate BYOD so cant root of flash a custom rom.

thanks all for any help.