Newly Created Records from On24 Missing First/Last Name

[#1]

Issue

New person records are missing data and only contain Email Address.

Environment

On24 Event Partner Launchpoint Integration

Solution

When Marketo pulls the Attendance Report, for On24 Events through the On24 Launchpoint Event Partner integration, as documented here:
ON24 Event Registration Updates | Adobe Marketo Engage

For any net new records to Marketo (people who registered and attended the event outside of Marketo), Marketo will only sync the Email Address and Attendance Status. This will result in records in Marketo that do not have complete data from On24, such as First and Last Name.

To avoid this scenario, it is recommended that all records are properly registered for the Event through Marketo, using Marketo Forms and Registration Campaigns as documented here:
Create Child Campaigns and Local Assets | Adobe Marketo Engage