I've installed Joplin via an AppImage. When I click the app in the dash, it takes two clicks for it to open. Once it's opened, if I close it and reopen it, it only takes one click.
I'm not sure why it's doing this. I suspect it's because I used appimaged to install it, which may not be initialising until the app is clicked once. And then on the second click, the app actually launches.
How am I supposed to debug this? appimaged is installed, so I don't know what's causing the problem.
Adding Joplin as a startup application and turning on the "Start application minimised in the tray icon" option fixed it for me.