Since the introduction of GDPR all WHOIS information is hidden by default for UK registrants of UK domains. You can change these via the Nominet Online Services portal and this article shows you how to do this.
1. Login to Nominet Online services at https://secure.nominet.org.uk/auth/login.html
4. Your details will now be viewable in WHOIS searches. You can check your UK domain at https://www.nominet.uk/whois/