Mac and iPhone reminders Not syncing. initial setup

thought I'd try apples reminders.

have MacBook Pro and iPhone 13, both updated to 26.

syncing contacts, calendar, keychain, photos, notes - all work (at least since AWS problems resolved..).

on both the Mac and iPhone, I turned reminders on in settings/account/iCloud.

on both the Mac and iPhone, I created a reminder or two.

the reminders showed up in the respective device calendars, but not on each other, and neither showed in iCloud web reminder or calendar.

MULTIPLE TIMES:

I have turned iCloud off/on for calendars, contacts, reminders.

I have restarted both devices.

I have logged out and back into apple account on both devices (losing various data btw).

seems like I'm missing something simple and basic...

thanks

Dan