I'll try to explain this as best as I can.
The domain is "generickeyword.com" and has been ranking well for the query "generic keyword" for quite some time. All hunky dory.
"generickeyword.com" is part of a much larger business which recently placed a link to "generickeyword.com" on another domain - let's call it "anothergenerickeyword.com" (this site has been around for a bit longer). "anothergenerickeyword.com" has now completely replaced "generickeyword.com" in the SERPs for "generic keyword". Same position as before, just a completely irrelevant domain. Even though it has nothing to do with the generic keyword in question - the keyword in "anothergenerickeyword" is completely unrelated.
"blahgenerickeyword.com" is still ranking, just a little bit further down. There are no links that I can find pointing to "anothergenerickeyword.com" using the generic keyword in question. The sites are hosted on different IPs. Google webmaster console gives no indication that "anothergenerickeyword.com" is relevant for the generic keyword.
I've already removed the link - so expect this will sort itself out soon. But this is one of the strangest things I've seen - anyone have any ideas?
