I have sent a survey to four participants.
All participants had tokens.
Participant D completed the survey and submitted it.
Participant D received the confirmation email.
Admin has not received any confirmation that a response has been submitted.

The Response summary table attached shows that
- one survey has been completed
- one full response has been received
- no incomplete responses have been received.

How is it possible for "Total surveys completed" to be different to "the total number of responses"?

Thank you.