Candidate does not receive message when template is "blank"

Summary:

Hello,

when I try to send a message via the send message button in the candidate profile's message tab, the message is not received by the candidate. If I do the same thing and select a template and send out the message, the message is received by the candidate.

Is this a bug? Do I have to confgure something so that "blank" messages can be received?

Content (please ensure you mask any confidential information):

Not received:

Received:

Version (include the version you are using, if applicable):

25A