I see.
From my own testing, it's not fixed in 17.3 BUT the workaround (Apple Watch turned off before connecting) works again, at least for me, which was not working in 17.2 and 17.2.1.
I don't think this bug affects people with iPhones that do not own Apple Watches, which may be why some people say it's fixed?
Also, seeing other posts from searches, it seems this issue has been a long-standing issue for some people, way before iOS 17 and Sonoma. Personally, I've never had a sync issue before iOS 17.