Created attachment 498980 [details]
Screenshot (Activities, Message Tray and a tiny bit on the Me menu when in overview)

Since a week or two, I have graphical glitches which seem to be dashed lines on top of some actors bounding box, especially the Activities (if I click on it), Message Tray (when it is shown), Me menu (when it is shown and fully if I click on it) and Date/Time (if if click on it).

This is not appearing for the windows, the dock, the workspaces or the system indicators (except the Me menu).

This is happening either in the overview mode or not.

Usually I know which component introduced the error, but here I downgrade the kernel, mesa, gnome-shell to older versions and I can not seem to find which one introduced the problem.

This is more if this ring a bell to a developer, because I do not have much more information, I should have reported as soon as I hit the update, which I usually do :-/