Visual Studio for Mac wont open

I’ve recently installed Visual Studio for Mac. Now, if I want to open a script from Unity, either by double click a line in the Console or a script in the Project tab, Visual Studio does not open. Or rather it will not change from Unity to Visual Studio and show the script. Unity will still be visible but the script will open in the background. This worked fine in MonoDevelop. Extremely irritating to have to manually change between the applications. Have anybody else had this problem and is there a way to fix it?

Also, is there a way to change how code tasks (like TODO, FIXME, etc) are formatted. I liked the yellow background in MonoDevelop.

Thank you!

Edit: I have selected Visual Studio as my main editor in Unity Preferences.

Make sure You did choose visual studio as External script editor
Go to Edit>Preferences>External tools