since 18.0 safari’s “listen to page” feature has been broken, and every point release has failed to fix it. it works fine for a day or two, then it just doesn’t read you the page anymore, and not even restarting safari fixes it, you gotta restart the phone.
i’ve tried it on an iphone that supports apple intelligence and one that doesn’t, to try to rule out if it’s somehow related, with and without airpods, and got the same results