Thunderbird doesn't carry over calendar events alerts/reminders after updates to it or reboots generally, at least in Ubuntu (24.04). I expected my events and reminders to carry over even after updates and computer reboots. They don't. I missed an important appointment because of that oversight. Thunderbird used to work. I doubt that there's an existing fix for this, so Thunderbird Calendar needs to be updated so that Calendar events alerts don't disappear after updates or reboots. Meanwhile, I'm looking around for email and calendar apps that don't have this problem. Thanks ###