Computer Microphone to Flex6600

I purchased a new sound card for use in my computer. I have always prior had my mic plugged directly into radio, but wanted to try something different. I am trying to use my mic plugged into computer for voice on my flex. I am not able to get this working.

Radio - Flex 6600

Settings - P/CW - PC/PR781 ESSB 3_2k

PC Audio selected on top right bar.

sound mic and speakers defaulted, receive audio working.

In the radio setup I have level meter during receive enabled, I see level movement.

when I use my foot peddle to key radio I get no audio. When I press MOX I get audio output.

Is this normal?

Also. Why does the DAX disable the PC audio? Makes use of software digital modes not usable.