I’m using Paperpile to read and markup papers in the Chrome browser on Mac (Version 80.0.3987.163 (Official Build) (64-bit)).
I have a paper open in the Paperpile viewer / editor on Chrome. Anytime I open or close another browser tab in another window it shows a toast notification with the paper reference in the Paperpile viewer / editor on Chrome. If I open multiple tabs, it shows the toast notification multiple times (see the attached image).
Not mission critical, but definitely a bug.