My contacts are being blocked. Even after I unblocked them, they would be blocked again

Hello C-b-a,

After you remove the contacts from the Blocked list, try restarting your iPhone, Restart your iPhone and monitor for the same behavior. Restarting can refresh the iOS, apps and connections.

We also recommend keeping your iPhone updated as those steps assure you have cleared out any minor software issues and are running the most current version.

Update your iPhone or iPad - Apple Support

If you still have questions, reach out to Apple Support directly, as this may require closer guidance: Get Support

Cheers!