Hey @Carey Rouse,
@Bobi N. has shared some really great insight!
How often are you testing the form either with your own test email or others? One thing that comes to mind when a behavior like this occurs is Klaviyo’s list bombing prevention function. This is to prevent malicious bots from impacting your account. However, this can sometimes be inadvertently triggered - especially with continued self testing.
Although you’re not getting the confirmation email in your latest test, is your profile still ending up on the list? If so, then I would suggest double checking your double opt-in setting in case it may have been toggled off.
If the double opt-in setting is still enabled, have you checked your spam, junk, and promotional folder? On small occasions, your inbox provider may also block the double opt-in email in case there are some misalignments within your DNS authentication.
David