Hello i_need_help_please2023,
Thanks for choosing the Apple Support Communities. We see you're not getting notifications from a contact you have recently unblocked.
To start, try removing the contact all together and re-add the contact to the Contacts app: Manage and delete contacts on your iPhone or iPad - Apple Support
Once re-added, test the issue. If this persists, next check to ensure you haven't silenced the contact in the Messages app.
- Open messages and tap on your contact
- Tap the contact icon at the top
- Scroll down and ensure "Hide Alerts" is toggled to the off position
For help with WhatsApp, we suggest checking out WhatsApp Support: WhatsApp Help Center
We hope this helps.
Cheers!