I thought I would try and see if I could duplicate the problem by just running PT4, Stars running, and switch user while I did other things. Tried this a couple of times (didn't play poker but did import observed hands from two tables).
So everything is working fine and then I install a new wireless mouse and right away the process
Pokertracker4.exe *32 jumps to between 16 - 30 percent. Wouldn't settle down to zero until I stopped import 15 minutes later.
I then started import again and
Pokertracker4.exe *32 jumps back again to between 16 - 30 percent. Wouldn't drop back down to zero.
PT4 also did a double import again. Note the time on the images and the same imported observed hands, 3 hours later: