No notification of voicemails

I switched from Verizon to Xfinity about a month ago (BYOD Pixel 2). Until today, I did not realize that I am not being provided with notifications when a voicemail is received, or any way to listen to voicemails, through the standard Android voicemail app. I have to manually dial in to see if I have any voicemails and to listen to them (several were missed over the last few weeks). What am I missing in order to have this function as it always has in the past?