iPhone/MacBook Air Calendar Sync Issue (no iCloud)

I recently got a new MacBook air and used the migration assistant to move all my info over; everything except Reminders ported over successfully. I do not use iCloud so sync my calendar and contacts by connecting to my MacBook. The first time I plugged my iPhone 14 into the new MacBook, I got a message that there were 700+ sync conflicts and opted to "Review Later". Every all-day event in the history of my calendar was duplicated onto the MacBook after this and recurring events were duplicated with odd recurrences (something that was every 3 months was duplicated and added as every 3 days). I fixed these on my new MacBook, tried to re-sync and selected the Advanced option to "replace calendars" on next sync. This somehow changed the dates of all-day events scheduled approximately 6 months prior and going forward (what was once a 1-day event became a 2-day event that ended on the correct date). I again fixed these on my MacBook and tried to resync but since then, nothing is actually syncing to the calendar from my MacBook even after selecting "Replace calendars".

Any ideas how to fix this sync issue? I can't find a way to "reopen" the popup I received about reviewing conflicts and I have no idea why this is happening in the first place. It's driving me crazy!

Other info that might be relevant:

• I still have my old MacBook Air, which is powered on
• Neither the old nor new MacBook are set to automatically sync
• Some of the issues are also appearing on info coming from public calendars, not only events I added (for example, Cinco De Mayo shows on my iPhone twice, both from the calendar US Holidays, one shows 5/5/24 and the other shows 5/4/24-5/5/24. On the computer, I only see the 5/5/24 event).
• I've tried adjusting the "Do not sync events older than X days" options and then resyncing with the "replace calendar" option. Still nothing.
• No events (all-day or specific times) are syncing from the MacBook to iphone or vice versa at this point
• I removed calendar from the sync and re-added--still the same problems, the info was added but not replaced.
• I do not want to use iCloud.