This is really a Nautilus bug and has been reported by others... It is quite annoying that many copy/paste commands happen (in pureOS 8) without any graphical notification. The copy dialogue does not appear in Gnome 3 and the pie chart progress indicator only appears for some copy/paste activities (not totally sure what the logic there is).
The work around of Alt-Tab to see the copy dialogue does not work in PureOS8.
The (better) work around of "install Nemo and use that" doesn't work because if you try to copy it says: gdkwindow-x11.c:5579 drawable is not a native X11 window.
My current (working) fix is to do all copy processes with rsync from the command line... however, I am not 100% sure that this is a fully "everyone"-compliant solution.