Just to be sure we talk about the same thing: what symptoms are you seeing? Does it show up empty, or does it do other stuff it's not supposed to?
So I have a Mac Studio running Ventura 13.1 and iPhone 14 pro max running 16.1.2
Both with screen time enabled and syncing work great
I recently got an iPad Pro 12.9 m2 and running 16.1.1 With screen time enabled the issue begins. Screen time on macOS and iOS won’t update and the spinning throber just spins. All 3 devices appear in the screen time list though but no usage update from either.
So if i reboot the mac or the iPhone then it screentime works again but in screentime devices the iPad is removed.
if I use the iPad then the usage on the iPad attempts to sync and we’re back again to both Mac and iPhone screentime not working But the iPad returns to the screen time list.
so thinking it was the iPad I turned off screen time on all devices and on a different day I brought each device back again. I enabled it on the Mac first and then the next day i did the iPad and they both synced perfectly.
so the following day I brought back the iPhone and then problem began again.
so again I removed all the devices and brought the iPhone back on day 1 and just the iPad on day 2 and they both synced again well. So I brought back the Mac and problem began again.
so basically only 2 devices allow screentime to sync regardless of which 2.
didn’t have this issue on iOS 15.
theres another thread on this here and after some researching there are some threads on this issue related to iOS 16 on apple discussions too and reddit But more so with their children’s iPads not syncing to the parent devices so i suspect its related .