Thanks for posting here in the Google Nest Community.
A few things: Are you having issues with your Nest display? If so, which Nest display model is it? When you play YouTube music do you have audio? Is the volume adjusted to your preference? Check the steps below on how to adjust the volume on your Nest display.
Turn up the volume
Press the upper volume button on the back of Google Nest Hub.
Turn down the volume
Press the lower volume button on the back of Google Nest Hub.
Check this link for more information.
Hope this helps.