I’d just like to add that I received my Midihub today and had similar issues trying to update to the latest firmware. I was using a recently built AMD 3900X PC running Windows 10 Pro 1909. When I went through the update steps the editor was able to erase the flash but then reported an error trying to write the new firmware. The error was something like “lost connection to midihub sync error 1”.
I tried several different USB ports but got the same outcome. Fortunately I was able to use a different PC (Surface Pro 3 running the same version of Windows 10 Pro) and was able to apply the firmware.
Please let me know if you need any more info to help track down the problem (or if it was user error ).