.45 no audio; .70 with audio
That sounds wrong.
With audio the voltage should read above and below the voltage with no audio. If you don’t get that then nothing will work.
Your descriptions are hard to follow can you post a schematic please.
I wasn't seeing voltage change before removing 100K voltage divider on audio input
If you remove the voltage bias circuit then there is no chance it will work even if you see voltage changes as your input is floating and will pick up all sorts of rubbish.