Error - Failed to accept the call while system phone call is ongoing

When I receive a call on my Android Phone, I try to answer it and a get the following message "Error - Failed to accept the call while system phone call is ongoing".  I have not had any issues with this until the last 2 day.  I believe there is nothing running on my phone at the time of the incoming calls and I am able to answer the call if I go through my laptop.  Yesterday, I uninstalled the Zoom App from my phone and reinstalled it and it seemed to work for 24 hours.  Any suggestions?