Ah, that explains that. I always found that feature annoying, I didn't know it was because my ISP misbehaving. I always get a century link search page when I typo urls.
https://en.wikipedia.org/wiki/DNS_hijacking
The new Google "did you mean to go to ?" nonsense is something else to add to that link!
My ISP (TalkTalk) claims to have an opt-out page but the forums suggest it's been broken for years, and today it is a 404. I have an open issue with the CEOs office to opt me out manually but they've been pretty useless so far.