As soon as I installed Android 8.1, (11/1) I received an error message saying "unable to make calls over Wi-Fi." Never had this issue before.

Moto G5 Plus from Consumer Cellular.

Phone does connect to my Wi-Fi network.

How to resolve?

Hi dedawson,

This is unexpected after an update. ER082 is an indication that your wifi may be working but your internet may not. Try power cycling your modem and router. Routers get messed up easily too if you have a lot of connections. I suggest you power cycle both at least once every week.

Regards,
JM
Motorola Support

**Please don't ask me questions by Personal Message; questions belong in the forums.

Hi JM that makes sense, except that the wi-fi was was working fine with browsers and apps etc. I’ll try power cycling and see what happens. Already did factory reset.

I never received this message before the Oreo update. Is it just telling me I have a cellular connection and therefore will not use wifi? Or is this saying I can't make wifi calls when no cell available? 

I don't know that I got that specific error message, but when my phone (Moto G5+, now unlocked from Consumer Cellular) did the upgrade OTA to 8.1 I could make wifi calls at first, but not today. So I restarted my phone and it works again. Something gets corrupted over time apparently between the handset and the wifi router (in our case, a Comcast cable wifi router).

I have the same problem you do, except I am on T Mobile.  Wifi calling works for about 24 hrs then quits and I get an error.  I have to restart to get wifi calling working again.  Then 24 hrs later it quits again .  I've called T mobile who pointed to Spectrum who pointed back to T mobile.  T mobile advised to open up a UDP port on my router.  Haven't tried that yet (will need help from Spectrum).  I have qty 4 MotoG5+ phones in my family.  No issues on the phone that still has Nouget.  I'm wishing I never upgraded to Oreo.

After a couple of weeks with the Oreo upgrade, my phone will connect to wifi calling with T-mobile after reboot but will drop wifi calling after a couple of hours on wifi.  Only way to reconnect is to reboot.  Because it will connect and make calls over wifi, I do not believe it is a network issue but rather a bug in Oreo.  Same thing happens when I at work on wifi.

After OREO upgrade, I have the same issue of wifi calling failing within 24 hours of phone restart.  I get a REG 99, Reg 082 or Reg 081 issue. Restart of phone resolves until it fails again within a day. I've called MOTO, T-Mobile, SPECTRUM (ISP) and ASUS.  Here's what I tried:

1.  Reset wifi, bluetooth, mobile  >> Did not fix

2.  Performed wipe cache partition >> Did not fix

3.  Performed factory reset of phone >> Did not fix

4.  Opened ports 4500 and 500 on router >> No issues for over a day now

May be some hope in #4 above.  Unable to add IPs to same open ports for other Moto G5+ phones I have in the household.

To add to my previous response about opening ports to resolve wifi calling issue:

1.  I have set up static IP for my phone (on both phone and in router

2.  I opened up ports 4500 and 500 (both UDP) for my phone in the router

So far this has resolved wifi calling on my phone, but time will tell.  Previously, I can get wifi calling to work after a restart but it would stop working within 24 hours.  I am on day 4 with wifi calling working after static IP set up and opening ports. 

I have a total of qty 3 Moto G5+ phones that have recently been upgraded to Oreo 8.1 and all of them have the wifi calling issue after the OREO upgrade.  I have just set up the same static route and open port proposed fix for the remaining phones.  I had to use different ports for each of the other phones since you can only assign 1 open port to 1 IP/MAC addx.  I'll report back with results later.

I have exactly the same message after Oreo update. ER082. Which of the above solved the issue?