Hi @jordansh,
Welcome to the Auth0 Community!
First, I have gone ahead and tested the Post-User Registration Action and did not find the same results. During the sign-up flow, I found the Post-User Registration Action only execute for non-existent users (new users). Given that, I can confirm that the Post-Registration Action is working correctly.
Next, I understand that you have not been able to get your OTP sent to you when using Passwordless.
Could you please elaborate what type of Passwordless you are using, if it is SMS or Email?
Thank you.