Took delivery of a EM Smart Fiber laser which connected right away to my iMac that I dedicated to the EM Smart. It worked very reliably for weeks. Then I started getting connection failure and tried every trick in this forum with little success. From new adapters to a USB-C to Printer USB, etc… I TRIED EVERYTHING!!! I swore it had to be the comm board in the EM Smart was bad. Tried contacting them. You know how that went! On the forum I got to the thread that talks about the issue being the USB 3.0 not working with the EM Smart USB 2.0… So I went down that Rabbit hole. Dug up my old usb hubs and adapters and tried every possible config and LB software version. it connected but not reliably.
So I bought one last set of older USB 2.0 adapters from AMAZON.
the one at the top of my adapter pic was useless but the USB-C to USB-A Female succeeded 100%.
ROCK SOLID EVER SINCE!!!
Note- im running 17.06 and have not dared to run 20.