I've been using Lightning calendar for years, in the last 10 days or so, it's become sluggish.
When a Reminder comes up and is dismissed, the empty dialog box sits on the screen for 15 or 20 seconds before disappearing. I used "find events" to edit the ics file down from about 500kb to 181kb, but it didn't help.
Any ideas about how to fix this thing?
I'm using Thunderbird 102.4.2, o/s is Ubuntu 18.04.