@pihop13 Hello, if the firmware of the phone corresponds to another country of origin and not from the UK, you will not be able to receive local updates. I do not know if this is the case.
If this is not the case, you can try updating with the Samsung-Smart Switch app. Greeting.
If you're unable to update the software using SmartSwitch, another option would be to perform a Factory Reset. This will delete all data on your phone and return it to factory default. Once you've done this, proceed to perform the update again. If you're still unable to do so, I'd advise heading down to a local Samsung Support Centre.
For more info on Factory Resetting: https://www.samsung.com/uk/support/mobile-devices/how-do-i-perform-factory-reset-on-my-mobile-device...
To find your nearest Support Centre: https://www.samsung.com/uk/support/service-centre/
I'd definitely recommend getting this inspected by one of our engineers. If you're unable to head to one of our Support Centres, the Social Media Team can look into raising this for you. You can reach out to them by dropping them a message on Instagram, Facebook or Twitter.