Welcome to the community @the Falcon
As you state that contacts are being added to your form’s target list, failed double options aren’t the issue.
Do you have smart send enabled on that discount email? If so, a contact who has received an email within the smart send window will be skipped from your discount email.
Have you reviewed your flow’s recipient activity for the discount email to see if contacts are being skipped or other reasons for not receiving it?
Have you checked the list the form is submitting to, is the same list triggering your discount flow?
Can you share the flow that’s not sending the discount email including any trigger/flow filters?
Regards
Andy
I would check to see that skipped count on the email for sure! That’ll list out fully the different reason’s someone didn’t get that message.
If you’ve been testing with the same email address, that’ll also affect you re-entering the flow.