Those voltages look way off Jeff
You say you get the sounds in the demo and squealing is the main problem but with the voltages given it wouldn’t work properly pin 4 should be ground 0v pin 8 power supply around 9v the other pins should all be around 4.5v
Are your readings 0.5v pin 1 and 0.1v etc aside from pin 8 which jumps from 5.7 back to 0.1v?
Did you take the readings the normal way by putting your black probe on a circuit ground point and touching your pins with the red probe with your meter set to 20v dc
I’m just confused that it worked aside from the squealing with the voltages you’ve given and suspect your meter may be set to 20v ac