Re:
“I had the same problem. I am with AT&T and have an iPhone 6s, so that may make a difference. I typically turn Suri functions off because it drains the battery. After upgrading to IOS 11 I tried everything that I saw on the forums such as: Airplane mode on/off, reset, reset of ntwk settings. None of these worked. The key I found is to go to Settings> Suri & Search >turn on "Press Home for Siri". Then do a reset (hold home button and on/off button at the same time for 10 seconds). Once I did this, the visual voice mail worked again for me.
BTW, I went back in to the Siri & Search and turned that funtion off again. Visual voice mail still works...........Hope this helps you.“
Thank you! I had the same problem. I have come to depend on visual voicemail and was worried . I also had Siri turned off, and I turned it on and reset as you described, and my visual voicemail is back! Now I am going to turn Siri back off. I opened an account here just so I could reply and thank you. Best answer!