I was going to comment this. My experience matches yours, the home page shows videos I may be interested on watch, and the subscriptions page shows videos from my subscriptions. Watch something new and you get related videos for a couple days, but ignore those and they disappear. I also like the occasional videos from old subscriptions or old watched videos, reminders from time to time.

I do not have the paid subscription though, but I do use only android (never web).