Cannot receive incoming calls from AT&T numbers

Did you fix this issue? Our office is having the same issue and we cannot recieve calls from ATT Frontier or U.s. cellular

@JillM, I see your case and it looks like support recommended that your team connect with you ISP about the issue and call us back if that didn’t help. 
Were you able to connect with them?
Let us know how we can help you move this forward.