Email notification does not pass on results of linked column

I have an automation that sends an email notification with the number of participants for an event plus the names of the participants. However, only the number of participants gets sent, the names not.
The number of participants column is a countlinks link formula referencing a linked column
The names of the participants is a lookup link formula referencing the same linked column

So, the table is called “Courses”
The linked column is called “Registrations” (link formula)

The email body says "{Courses} (references column in table) has the following number of participants: {Registrations} (countlinks formula referencing link formula column “Registrations”).
The names of the participants are (lookup formula referencing link formula column “Registrations”)

Am I doing something wrong?