Marketing Cloud CloudpageURL() link not reading data from data extension for added records in the Data Extension

We have an email linked to a CloudPage that has a smartcapture feature. The DE that is used for the email contains customer info which is exposed to the Cloudpage via ampscript:

%%[
var @emailaddress,@FirstName
set @emailaddress = AttributeValue("emailaddress")

set @emailaddress = Lookup("VisaAcquiDeJuly","emailaddress", "emailaddress", _subscriberKey )

set @FirstName = Lookup("VisaAcquiDeJuly","FirstName", "emailaddress", _subscriberKey )
]%%

Everything works fine and custom URL strings show for each customer, but if I add a new record to the original DE (Contact Builder > Add Record), their data doesn’t get passed to the cloudpage when clicking the email’s Link to Cloudpage button, and there is no custom URL string that shows up when redirected. How may I get the cloudpage working for new records?