can't sync contacts in iCloud

OK, this is REALLY frustrating. I keep my Contacts on my iPhone (iOS18.5) up to date, and my Mac (Sequoia) and iPhone are both competently logged into my iCloud account. When I go, on my Mac, to icloud.com/photos, all the photos on my iPhone are right there. When I go, on my Mac. to icloud.com/iclouddrive, all my iPhone Documents are right there. But when I go, on my Mac, to icloud.com/Contacts, the Contacts there are not updated, and are not identical to my Contacts on my iPhone. What the h is going on? How do I push my iPhone contacts reliably onto iCloud? The "Contacts" feature is enabled in iCloud settings on each device (yes, I toggled those on and off). Appears that everything is being sync'ed to iCloud from my iPhone EXCEPT for my Contacts. Yes, I've tried restarting the iPhone and the Mac. Lots of Apple pages on sync'ing Contacts, and I've tried everything.

Yes, there is this - https://support.apple.com/en-gb/101336, but that doesn't do the trick. When I toggle Contacts enabling on my iPhone I'm never asked to Merge or Cancel.

What I see in icloud.com/Contacts is an old version of my iPhone Contacts. So it must have sysnc'ed long ago, but hasn't in a long time.

Is there somewhere in the iPhone where you tell WHAT in Contacts to sync, and what not to sync? Specifically, for one contact on my iPhone, I have two home addresses- "Home" and "Other" (that person is in the process of moving). In icloud.com/Contacts, only the latter is shown.