I don't know really. But I do know that in the recent past, it became obvious that some miners were, for example, mining without verification (SPV), which suggests that they were not mining to any Bitcoin Core s/w, right?
They were still using Bitcoin Core to do that (if you didn't realise this then why post incorrect suggestions?).
A more careful reader would note that my post was as much a question as a 'suggestion'. No need to be insulting. Maybe you know more about the situation than me, or maybe you don't, but we can't know either way without having the discussion :|