Hmm, some USB2 devices get cranky on a USB3 connection.
But that would mean that the Poke5 is USB2? That would be depressing.
I always use my Poke3 on USB3 and I can verify that it is talking USB3.1 normally and USB3.0 on EDL.
Try
this utility while plugged into USB3.
See what the "bcdUSB" says. Also what "Open pipes" says.