Mailchimp Resubscribe

We are investigating an issue for one of our customer using Sage CRM 2020 R1

When a contact receive an E-Marketing communication and unsubscribe, Mailchimp is updating the SageCRM Opt-Out E-Marketing to checked.

If the user resubscribe via a Mailchimp page, the Opt-Out E-Marketing is never updated to uncheck (after waiting more than 24h).

The documentation does mention that it has no effect in Mailchimp if we manually uncheck the Opt-Out in SageCRM.

1) Is there a way to automatically update the contact if he resubscribe vis Mailchimp ?

2) When a contact Subsribe via MailChimp, the CONSENT page is not filled in. Is there a solution for that ?