I just bought a Mac Studio M2 Ultra. I have Sonoma 14.3 on it. I've been having issues getting the calendar notifications to work consistently. I've checked all settings and everything seems to be set correctly. At first there seemed to be an issue with Bitdefender Antivirus preventing calendar alerts, but I've completely removed the antivirus software and notifications are still not working.
I purchased a 21" M1 Mac in early November oof last year and am running Sonoma 14.3 (updated on the advice of a senior advisor at Apple Support). am having the exact same problem. Spent countless hours on the phone with Apple - tried everything. The Calendar app was one of the few apps I use on a constant basis. The notifications on my old Mac (Yosemite) ran flawlessly for 10 years, the alerts popping up on the screen on schedule every day when I turned on the computer. Made changes, additions, deletions regularly - not a single hitch. The current problem wasn't solved by using iCloud (which I’ve since turned off, as it caused too many problems among my various Apple devices - a constant babysitting chore which ate up hours).
In my opinion, there’s no excuse for this. If former iterations of the Calendar worked perfectly, there is no logical reason why updated versions shouldn’t as well.
On my M2 Mini, I get Home sounds but no banners, I get nothing from Mail. Notifications has been broken for every Sonoma release.
Fortunately, calendar notifications has started working again. I'm not sure why, but I'm glad it's working.
Sonoma 14.3 notifications alerts and banners not working
