Vi internet not working and one way audio on M31s

[raju_rangarajan]

Hi friends, I bought M31S last year and for many months now, internet doesnt work on 4G/VOLTE setting  for Vodafone. Any known issues with M31S and Vodafone in CHennai/India? Also am able to hear people on other end when they call me but they are unable to hear me. Things are better if I switch to 3G setting, call quality is better and internet I get 3-8Mbps (atleast mobile gets connected to internet in 3G). 

Options tried out:

1. Set network selection to automatic.

2. Reset network connections to default.

3. Reset  APN.

4. Checked and enabled 4G and VOLTE setting on my phone.

5. Checked with Vodafone Idea customer care that my SIM is 4G and VOLTE enabled.

6. Have tried to set to specific bands using Samsung band selector app and restarted mobile.

7. Issue happens during the day and I get little bit of internet during night (between 10pm to 6am).

Any solution that worked for you would help. Vodafone says its problem with my handset as they tried to use my sim in their handsets and it worked well. They tried with Redmi and Realme, Samsung mobiles. Their sim cards didnt work when installed on my M31s. Am running out of ideas and no solution to resolve the issue.

[Ashwinash]

What Sim card's didn't worked on your mobile bro ?

[raju_rangarajan]

only Vi (Vodafone Idea) sim doesnt work, Airtel and Jio works ok.

[Ashwinash]

Bro try resting settings of your samsung mobile. . Or try to change from automatic to manual settings. .

[raju_rangarajan]

yes bro, i checked by changing by automatic to manual and then to automatic, still no luck. Also reset to factory settings done, no luck.

[Ashwinash]

That means your Sim broken like that so buy new one bro .

[raju_rangarajan]

its new sim bro, like 3 weeks back only got it.....also same sim works on Redmi mobile which the Vi service engineer had as test mobile. 

[Ashwinash]

Wait for next update bro. No worries. Because vi is faster only both 3g and 4g .
Vi users are happy because we are having 3g and airtel , jio don't have that . . If they face 4g issues they won't get 3g . .

[raju_rangarajan]

Bro, problem is that Vi would be removing 3G services shortly, maybe in days or weeks time. Then I will be left out with Vi 4G sim but to only make calls by setting it to 2G.  Hence the concern, I agree, I have been using 3G till date, but what about once they stopped 3G? I trusted Samsung and bought a phone, now this is pure cheating to end consumers that its 4G phone but wont work on some service providers.

[Ashwinash]

3g calling, sms, net working very well for me . Bro