Welcome to Vodafone Community
May I ask are you also using an activated alternative network sim card i.e. one that connects to mobile data etc @trevormayhew ?
Are you currently in the UK ?
If so and your keying in the Nuc exactly then you may also need a mastercode also known as an unfreeze code.
Customer service on 191 or Live Chat can help you with this and or provide the Nuc email address.
Current Phone > Samsung Note 9 _512Gb > Model: SM-N960 Hybrid-Duos.
Samsung One Ui / Pie.
Samsung Gear s3 Frontier Watch.