Unblock Youtube User -

Go to YouTube.com and make sure you are signed into your account.

You will see your list of blocked accounts. Tap Unblock next to the user’s name. unblock youtube user

Look for the tab that says Blocked users (sometimes labeled "Hidden users"). Go to YouTube

So, how do you undo it?

Click on your Profile Picture in the top-right corner. unblock youtube user

A pop-up will ask you to confirm. Click Unblock again.

Open the YouTube app and tap your Profile Picture in the bottom-right corner.