[Elecraft] FT8 Driver Issue

[Lee Murrah]

I am running WSJT-X in FT8 mode on my K3S using the onboard sound card and USB cable and VOX for keying. My computer is a Mac running Catalina. The K3S manual recommends setting the drive at 4 or 5 bars to avoid distortion by the ALC.. When I use the audio output slider set the drive level, the display jumps from no bars to 6 bars, and vice versa, and nothing on between.  I have also tried using the MIC level and the POWER slider in FT8 with the same results.  The software id decoding fine. Can anyon suggest what the problem might be?

KV5M
Lee