We needed to remove an integration according to Google's request...
However, there is still a way to make your YT playlist play in VOX:
1) Open VOX and Press Comand+U
2) You will see a window appeared above VOX
3) Open a YouTube playlist you would like to import to VOX and Copy/Paste the URL to VOX window.
4) Watch your YouTube playlis is avaliable in VOX app!