I've been reading with interest all the related problems, and suggested solutions to this. It's really great that everyone is trying to solve it. Nothing has worked for me, however.
The most valuable advice seems to be that one should activate through "youtube.com/activate" rather than "youtube.com/tv/activate". But I cannot do either, because the only choices given me are to:
1) Sign in with your TV
2) Sign in with your phone
There is NO option for me to sign in on my laptop, which I think every other ROKU app allows. And signing in on the TV only brings me back to this broken ap, with no search history. But the fact that some of you were able to use this solution suggests to me that I may be either missing something/doing something wrong; or have a different device, software, or setup. What thinks you all?
Meanwhile, an odd semi-solution: I don't sign in at all. Strangely, that allows my search history to stay! Of course I have none of my subscriptions, but with the search history, I can just as quickly get to my favorite channels. For instance, I search for "samcrac" once, and then when I want to go the channel again, it is either there on the list, or I just have to type "s" or "sa" and I've got it.
And it seems there are WAY LESS commercials. When I am logged on, for even the shortest videos, I get double commercials every two or three minutes... and many are not "skippable". But when not logged on, there are far fewer commercials, usually just two at the beginning, and once more in the middle. Ahhhhh... and, they are usually allowed to be skipped.
Of course since this barrage... curse... flood... of commercials that Youtube had unleashed on us... I find my self on my laptop watching far more often, because here I can control the ads... that is, use my old buddy which rhymes with "cad docker".
Anyway, great input from others, and I'm glad it worked for many... maybe someone can tell me what I'm doing wrong, so I can possibly get it to work for me.