@iamstressed 

Hi, you mean the MR6500v with Vodafone SIM cannot make any outgoing calls or receive any incoming calls, right? 

Did you enable VoLTE on the MR6500v? please confirm it on Advanced->Telephony->Telephony Mode, it is on VoLTE mode by default but the VoLTE is off, which means it will fall back to 3G for voice service, is there still 3G service in your area?

If problem still exists no matter the VoLTE is enabled or not, please insert the same Vodafone SIM in your smartphone, then try to make calls or receive calls on the phone, please also monitor if the smartphone will stay on 4G when on call or fall back to 3G or 2G, which is very important.

  @iamstressed 

Hello, to assist you efficiently, I've forwarded your case to the TP-Link support engineers who will contact you with your registered email address later. Please pay attention to your email box for follow-up.

  @iamstressed 

Hi,

I've checked your case and talked to the senior engineer, he is waiting for your email with new TeamViewer ID and Password, please note that TeamViewer password usually changes every time when you re-open it unless you set a fixed one manually.

So please reply to the previous email with your new TeamViewer ID and Password when you are ready.

In addition, EOL status will not affect the warranty, please don't worry, let's see if the issue can be located and solved by the senior engineer after the remote session.