Not sure of the difference between the Pi 3b and b+ models.  I have detailed instructions though on setting up the newpacs on a Raspberry Pi 3b+ on page 28 of this thread.  I have not spent much time with these devices on Windows as I ran into stability issues once I tried, went the Raspberry Pi route and never looked back.   One thing to note though, if you are only going to run 1 - 4 newpacs, then a Raspberry Pi 3b+ will be fine.  If you plan on getting more than that or any R606 then you will need to get minimum Raspberry Pi 4.  As the 3 series ran everything off one bus lane which created bottlenecks.

My suggestions since the Pi's are easy enough, reinstall Raspbian on that device, and follow the steps on page 28 for setting up the newpac  on a raspberry device and see if this resolves the issue for you.