What happened to my PhoneFusion?

[Mbun2]

PF Voicemail worked fine for years. Now all of a sudden there's a call forwarding problem. PF is saying it's the carrier. Carrier is saying they haven't changed anything, it's the app. I can call into the PF phone number & get my voicemails, but can't use the app. Very weird. Consumer Cellular is saying their forwarding code is **21* and that it forwards all calls, no conditional forwarding. PF uses 004. Why was it working all this time? & Why did it stop?

It stopped working maybe 2 weeks ago. I have a Moto G5, Android 7.0.