Thanks all. I have it plugged into a USB hub for now and it’s working. It seemed a little flaky getting going, but it’s survived a core restart. Not sure what will happen if I try and do a host restart, but we’ll see. If people are handy with a soldering iron, there’s another thread HERE where the OP has a fix for the older ZStick Gen5 sticks so you can plug it directly into the pi4 again. I may try that if the USB hub method proves to be unreliable like a lot of users report.