Win10 - Firefox - Ublock origin - Youtube - does saving video to playlist work?

Question

YouTube

Hey!
When saving a video to a playlist, the error "Do you want to add this video to a playlist?
To do this, you need to log in to your account." - I click "Login" - 405. That's an error.
The request method GET is inappropriate for the URL /youtubei/v1/browse/edit_playlist. That's all we know.

Although I logged into my account and can open: subscriptions, history, playlists.
Does someone with the same "set" save to playlists work?

Answer 1

The problem is Kaspersky. Representatives said they would fix it at the end of October - beginning of November.
Now you can uncheck the box in KIS (at your own risk) with "Inject web page interaction script into traffic" (Settings > Advanced > Network) and it will work.

Answer 2

what is interesting - in chrome youtube works fine. only in FF it started to fail. It's already mid-January and this bug hasn't been fixed yet