If you had given the name involved people could have helped you better, as the answer depends on the TLD. Also it depends on how you do whois lookup.
So a generic answer to help you understand how things work, assuming we are speaking about a gTLD (otherwise most of the following is moot), and NOT
When you register a gTLD you give all sort of personal information to a registrar: registrant, admin contact, technical contact and even billing contact maybe.
The registrar stores that in its database. Then the registrar has to send data to the registry when the domain is registered. As this point the registrar can elect to send the "true" data, the one you gave, or if it has some sort of privacy/proxy service (for free or not), it will swap this data and send something else to the registry.
The registry obviously stores what the registrar has sent.
(There is a deviation here if we are in
net land as these TLDs, at least still for now, do not have contacts at the registry, so the registrar does not send contact data)
Now, in this specific case (gTLDs) there are two whois: due to an ICANN requirements, both registries and registrars need to have a whois server (and since 4 months, event an RDAP server, and you should prefer RDAP over whois), and you can query it. Each party is of course only able to reply with the data it has in its database: the registry will reply with whatever data the registrars has given in the first place, and the registrar will reply with either the true data or the privacy/proxy ones if the service is enabled.
This is all the technical part. But the regulatory framework has changed in May 2018 when finally ICANN, reluctantly, put in place what is needed to be better aligned with new rules, like the GDPR.
To summarize, because of it, now you won't see any personal data through whois on port 43. You may still see some through web whois, often after some captchas or some form of authentication to deter mass collections.
All the above could explain why you do not see your data, but it really depends on the TLD, and how you do whois queries, two points missing in your question.