Hello from Australia I am also experiencing this issue and it is driving me Crazy. I have Youtube Premium and i also have a 2nd Youtube channel connected to my youtube account for uploading videos. I need to switch between the two, however i cannot sign out due to the issues Theorist has described. I click the youtube premium icon up the top right of youtube, it loads the page but signs me out. I click sign in, it redirects here: https://www.youtube.com/youtubei/v1/browse?key=AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8 405. That’s an error. The request method GET is inappropriate for the URL /youtubei/v1/browse. That’s all we know. I then get bombarded with adds in youtube because its not recognizing that i’m signed in with youtube premium. I contacted support and they first fixed this by opening KIS going to Settings and selecting manage settings, restore to default. I have tried this since the problem re-appeared and it is not fixing the issue. I need to be able to access content i have paid for - which KIS is now preventing me from doing - and switch between youtube accounts so i can upload content to my channel. Can you please advise when this fix will be rolled out and if you can put me in the beta testing group for the fix?
