You can go to Profile → Modify Profile → Notifications to verify, if you are not actually subscribed to some threads. It’s possible the reply has been removed before you came to check for new posts. I’d say this is the most likely scenario.(1)
If it’s not that, verify the link address. If you are reading in plain text, copy the domain name. If you permit HTML, copy the target address (not the one displayed), paste to a plain text editor, copy the domain name. Having that domain name in plain text, compare it with “eevblog.com”. If some letters do not agree (e.g. ‘e’ or ‘o’ have some 1-pixel dot added somewhere, or ‘l’ is actually ‘1’ or some letters are suspiciously uppercase), consider it a phishing attack. If not, the test is inconclusive: you can’t rely on your eyes. Preferably use a computer for comparison: a programming language, Unicode-capable spreadsheet, a diff tool, even calculating hashes.
If it’s the same, likelywe have some mystery. Check if the thread with ID/name used actually exists. It’s possible somebody is spamming users to get answer faster.
(1) I am not dismissive and it’s very good choice, that you reported the situation. But in practice PEBCAK is more common than attacks. And nobody is immune. We are just humans.