I do have one other curious issue since upgrading to Sierra. At shutdown or restart, the iMac no longer gives the typical spinning circle it used to. I'm not sure what it's called (it's not the spinning beachball), it white on a black background that rotates clockwise and looks like the hash marks on a clock. My screen just goes blank, making it hard to determine if anything is happening until the restart or shutdown occurs.
Anyone have a clue what might cause that indicator to disappear?
I see the same thing in Mojave; I"m not sure when it began, but I"ve experienced it in the past few incarnations of macOS. (I call it a "work wheel", but I"m not sure if it's the correct term.)
