I've come to using TeXstudio having written most of my chapters in WinEDT. I'm now adding more writing in the document. I'm using the MacOS version of TeXstudio, coming from using WinEDT in the Windows environment. I also used TeXstudio in Windows for a couple of days before migrating to the iMac.
In two areas of my document, and only associated with those I have been working on today when using MacOS, I have a vertical green bar in the margin. No text is highlighted.
The document I am working on is in the cloud.
Saving the document did not remove the green bars, but shutting down TeXstudio and opening it again did. The green bars are now gone.
Are the green bars some type of "this is content added in your current TeXstudio session" indicator? I had a look under "Configure" and didn't see anything obvious in there.
I don't recall seeing these green bars when using the Windows version of TeXstudio.