Users getting error when trying to see YouTube video with the message "Video unavailable. This video is restricted. Please check the Google Workspace administrator and/or the network administrator restrictions."
The error message on top of the YouTube video will look like below:

This issue involves Content Filter, and may happen even if YouTube is not being blocked by any content filter policy.
There's an option on CFS object that enable or disable Restrict Mode on YouTube.
Go to "Object" > "Profile Objects" > edit the profile of the user groups affect, and on the advanced tab you should see as below:
Disable the option "Enable YouTube Restrict Mode" and hit "Save".
This should solve the issue.