Hey @amarin27 

Thank you so much for asking the Klaviyo Community about why your list triggered Welcome Series flow isn’t sending to all of your customers who appear to have signed up. Hopefully together we can get this solved quickly for you.

There are a couple of key items you will want to check on your Welcome Series flow settings. Are the contacts being added to the correct list that you are using to trigger the flow? Is your list set up for Double vs. Single opt-in? If the list is set to double opt-in, your contacts must complete both steps before they will move through the flow. A profile is created for them in the list as a placeholder, however until they complete the steps they will not be marked as consenting to your marketing and therefore not move through the flow. Do you have any additional filters or conditional splits set up that may be interfering with your contacts moving through the flow?

Also check out this other community post about troubleshooting Welcome Series flow, you may find the additional information helpful! 

Thank you so much for contributing to the Klaviyo Community and each members success by collaborating in our community!

Hi Stephen! 

Yes, it was the double-opt in. I didn’t realize that was on place. Thank you so much!