If you're experiencing persistent issues accessing YouTube, contact your internet service provider (ISP) to see if they can resolve the issue.
Are you trying to unblock someone so they can again? how to unblock on youtube
Click the next to the name of the person you wish to unblock. 💡 Key Things to Know 💡 Key Things to Know Unblocking on YouTube
Unblocking on YouTube is straightforward when the block originates from your own account (Settings → Community & permissions → Blocked users → Unblock). However, if you are the one blocked by another user, there is no automated unblock feature; negotiation or account switching is required. For content-based blocks, VPNs or age verification are the primary solutions. Click at the bottom of the window to apply the changes
Click at the bottom of the window to apply the changes. How to Unblock Someone on Mobile (iOS & Android)