For me, the plist having write access for everyone was the problem. I did chmod go-w on it and it worked. Why is the launchd system so fragile and uncommunicative? It's like they don't want developers to use it. I've raised a bug with Apple. https://feedbackassistant.apple.com/feedback/15371740

I had a similar issue - what I was doing was calling removeAllPendingNotificationRequests immediately before I scheduled the new ones, just to clean everything up before reseting. The problem with that is that this method does the actual work on a background thread, so if you immediately add new notifications it's possible that they are deleted by the deferred removal.

This is all rather painful isn't it! There is a page with sizes on here - you need to go really small! 42px. Make sure you add the 2x and 3x versions of you image to avoid it looking blurry. https://developer.apple.com/design/human-interface-guidelines/complications#Circular