Calendar sync to iPhone or iPad using USB cable does not work in Ventura 13.4.1

Mine stopped working earlier this week: new events would not sync. I contacted Apple Support who referred me to Safe Mode. My problem was that the "selected calendars" list was not updating, after I created new calendars, renamed one, and deleted others, in the Calendar app. In Safe Mode, this list appears to get updated when I unplug and reconnect the iPhone via USB, and things work as expected after that. And outside of Safe Mode, I can sync events normally, but the selected calendars list does not get updated. I have turned off everything in Login Items yet the list never updates. (launchd is next). So, my workaround: boot to Safe Mode once after making any changes to the calendar _list_. (I hoped this stale list was in a file somewhere that I could just delete, but apparently not.)

Hello,

Since updating macOS Big Sur to Ventura v13.6.1 in a family's 13" Intel 2020 MacBook Pro about a month ago and synchronizing two folks' iPhones (13 & 11 Pro Max's v16.7.2) in two different macOS accounts, I found issues with Calendar events in both macOS Ventura v13.6.1 and iOS v16.7.x:

1. MacOS' Calendar shows missing new, deleted, and updated events from iPhones. How do I get all iPhone's calendar events to show up in macOS' Calendar? Is there a way to force it? I know it can go the other way, but iPhones will lose their newer data. :( And yes, I checked to see the calendars are selected (all enabled).

2. After the first synchronization for each iPhone after macOS upgrade, both iPhones and macOS' Calendars showed many duplicate events.

Users don't use iCloud for Calendar and others, except Find My, and any other non-Apple third party services and apps for calendars. All synchronizations are done through lighting-USB2 cables. What's going on? Is there a known bug or something? :(

Thank you for reading and hopefully answering soon.