Had that on our 40 Ocean. It actually came from two places. One was aft and the water came in at one of those
deck holes left from when the teak was installed. Did the same treatment as for the rest, cut out the failing short piece of caulking, drill the hole to get a clean edge, fill with epoxy, then re-caulk the deck.
That didn't stop it all though, and after much poking around with the USB inspection cam on a rainy day, I eventually traced the remaining water ingress to the U-bolts installed just forward of the lazarette lids, which originally were attachment points for the jacklines. Those turned out to be leaking on both sides, and getting to the nuts on the inside was an absolute horror - both required cutting access holes into the GRP ceiling liner in the aft cabin and one was even glassed over and right above the bulkhead, which luckily was very rot resistant.