4G calling compatibility for OnePlus 5T on Vodafone in UK

[kuweihang]

I'd appreciate any advice here, I've not had great help from VF online support.
I have a OnePlus 5T which I purchased in June 2019. I have had it on VF UK network since I bought it. I need to my phone to 4G calling as VF will discontinue 3G calling later this year. According to the phone specs it supports LTE so I'm hoping it will switch to 4G calling. I don't see any specific setting on my phone to force it to switch to 4G calling, if I can believe some comments https://xender.vip/ I've seen in forums then it should happen automatically.
VF has a 4G calling compatiibility check based on IMEI on their website and my phone fails that check, and it advises me to purchase a new compatible phone from their list. But I'm very happy with my OnePlus 5T, I won't be getting a new phone just because of this issue.
Worst case I think is that my phone will drop to 2G calling - as long as that's not awful I'll bear with that. Or could I be lucky and this phone will switch to 4G calling despite it failing the IMEI check?

[Amanda]

Hey @kuweihang - I appreciate your concern with this and wanting to make sure everything's ready for the future. 

Have you checked you've enabled 4G and WiFi Calling on your account? You can see how to do this on our How do I set up WiFi Calling help page. 

[srimany]

have exactly rhe same issue. a well informed answer on One Plus 5T would be very helpful. Vodafone IMEI check says NO.  The support forum has either no answers or mindless inane ones with links that have already been checked or do not work. My understanding is that One Plus 5T supports 4g not necessarily on both sims nor VoLTE on both simultanseously.

But enabling only the vodafone sim for data, should work? Perfectly happy with current phone