Can not register after deploy custom client

[tranvu14]

Hi, I need help in this.
I use Amazon to run my website. In the first run, after use template, it work fine for both register and sign in.
But after I deploy a custom client, I do not receiver any email have magic link for register.
But I still can sign in by magic link.
After I reset stack, it work again. But after I deploy my client, It can not sign up again.
Can anyone help me in this? Thank you!