Customers automatically subscribed to newsletter in Sailthru despite not selecting "Sign Up for Newsletter" during registration

[yavuz]

Issue Description

When a new customer registers on our Magento 2.4.6 store, they are automatically being subscribed to the newsletter in our Sailthru management panel, even when they do not check the "Sign Up for Newsletter" checkbox during the registration process.

Expected Behavior

Customers should only be subscribed to the newsletter in Sailthru if they explicitly opt-in by checking the "Sign Up for Newsletter" checkbox during registration.

Actual Behavior

All new customers are being marked as subscribed in the Sailthru management panel, regardless of their newsletter opt-in choice during registration.

Steps to Reproduce

1. Navigate to the customer registration page on the Magento 2.4.6 storefront.
2. Fill out the registration form with valid information.
3. Leave the "Sign Up for Newsletter" checkbox unchecked.
4. Complete the registration process.
5. Check the customer's status in the Sailthru management panel.

Additional Information

• Magento version: 2.4.6
• Sailthru integration: 2.5.0

Can you help me solve this issue?