Echo on ipad

My setup - 

Ipad pro - 17.3 ios, zoom app is up to date ( I use the app, not safari browser)

Shure sm 7 connected via usb c to my ipad with an apple usb c to usb a connector

I have run 3,000 meetings with this setup, no issues. 

Recently multiple people on the other end have been experiencing an echo.  It is their voice that echoes, and it is ONLY when I begin a screen share.  Prior to that, there is no echo.  Any solutions would greatly be appreciated.