Gmail spam filter not working?

Nope. It still works great for me.

Better than ever, even. For the vast majority of crap they're just deleting it sight unseen. My GMail spam folder used to have over 10,000 messages (with them auto-deleting after 30 days). Today it has 192, which is small enough to search for the occasional false positive.

(Real false positives are very rare. I do try to mark things that were legitimate law-following commercial emails, so that I can unsubscribe but signal that they're OK to anybody who might actually want them. Aggravatingly, the Red Cross did not actually support its unsubscribe link, so I gave up and let it be marked as spam.)

Very noticeable over the past few months. Had almost forgot that spam existed until recently.