I've found suggestions on the official MSFS flight simulator forum regarding this issue, but none  have worked for me.

I can request and receive ATIS and if I tune clearance I can hear the controller interacting with other aircraft.  However,  I can’t get default ATC to respond to my key or mouse presses when I click on the ‘Request IFR Clearance’ prompt.

I’ve tried loading a Simbrief flight plan on the main menu. Manually inputting the dest/arr and letting MSFS create the plan, etc. Inside the aircraft I’ve imported a plan to the tablet, not imported a plan to the table. Created a plan in the FMSG, not creating a plan, and imported the Simbrief plan.

I honestly can’t think of anything that I haven’t or could try, so if someone has some suggestions I would appreciate it.  Not being able to get an IFR clearance really affects my flying with live traffic.

BTW, this problem seems unique to the A320neo V2.

Thanks,
Ernie

My apologies.. Solved.. Frustrated user error with call button.