Payment request is saved as draft and not sent by e-mail automatically

Hello, I have just created a payment request for a sales invoice, but when I validated it, it is saved as draft, and the mail does not appear to be sent.

This is the second payment request I made. When I created the first one, I can see the sent e-mail in the comments section.

Why in this new case, the email does not appear there?

I know I can sent it in print format page, but in that case, I have to re-enter the message body.

What was missing when I created this new payment request?