Issue is that incoming calls until answered or rejected stop my internet connection!Who is your carrier? Some carriers do not allow both at once.
Are you using VoLTE for calls?
Were you able to do this before and suddenly it isn't working, or is this the first you've noticed?
Google says to check these things, https://www.google.com/search?q=no+...LjO4B-AJwgcGMC45LjExyAdC&sclient=gws-wiz-serp.