I've been using an EFW2 for many years now (I'm now on my second one purchased about 2 years ago). The problem described below happened with both filter wheels, but the problem has been getting progressively worse over the last several months.
What happens is that when I first power on everything Windows 10 does not recognize the filter wheel. There is an "unknown device" in device manager. If I unplug the power to the EFW2 and plug it back in then everything works properly.
This used to happen once every 5-6 times. Now it happens every time. I'm using the latest driver package (Native and ASCOM).
Any ideas?