content: I can report on this. I've used chrome via VPN and firefox via VPN from foreign countries and I've seen some strange things. Even after clearing all cookies, everything, Google still knows I'm in a foreign country - maps, youtube, etc all give me the local country's experience. Amazon video via Chrome will fail to play because of region restrictions (in incognito). Thankfully, amazon video via Firefox still plays and doesn't have any region problems. This is strange because youtube in FF still knows I'm in a foreign country.  Back to OPs stuff - I've seen the same thing about suggested videos being similar between incognito and not-incognito windows. I thought maybe I was being paranoid and wrote it off, but if OP is seeing it too, perhaps I'm not.