For end-users who can’t wait for Plex to fix this issue, you can install a Chrome extension that allows you to modify the HTTP headers sent to servers, and force the Accept-Encoding header to always send the value gzip, deflate
I tested with the Requestly extension, and the following settings:
You can import this rule in Requestly by visiting this URL after installing Requestly. Use the Import List button in the top-right corner.
And I (and you!) can now play YouTube videos without problems in Chrome. Yay!