No USB input level on Sierra 10.12

I recently updated to Sierra 10.12 …when using Audacity 2.2.2 with my USB Scarlet 18i8 the audio is getting to the Mac ok Apple/system preferences/sound the USB device is detected and the sound level is good. When I open Audacity nothing is getting through. I have followed all to advice in the on line manual checking Audacity system pref ‘quality’ settings match and USB is selected as input and output port but still nothing … I’m lost as to what to do next, can anybody help?

Apple may have rolled out the same change to Sierra as they did for Mojave; See if this helps: