We've got 3 Samsung devices here, all on 2 Degrees' VoLTE compatibility list, none of which offer the feature in the menu where the option is supposed to be.

The devices are:

• Galaxy Note20 Ultra 5G (SM-N986B/DS) - Bought from 2Degrees
• Galaxy A31 (SM-A315G/DS) - Bought from Vodafone
• Galaxy S20 (SM-G980F/DS) - Bought from 2Degrees

All 3 devices have new(ish) 2 Degrees SIMs in them, none of them show the "VoLTE" option. None have been "rooted" or had anything "done" to them.

Put a Skinny SIM in them, the VoLTE option appears instantly. (So presumably not a device issue)

Put the 2D SIM into any other phone we can lay our hands on without /DS in the model string, and the option is available. (So presumably not a SIM or account issue)

Has anyone had any joy getting VoLTE to work with a 2 Degrees device which supports Dual SIM? We don't actually need the Dual SIM feature, it just happens to be what the devices support when we bought them (I don't believe there was an option for a non-DS variant). I'm not saying that the /DS is the cause of no VoLTE, it just seems to be the most obvious common factor.

Have been into a 2D store and some experimenting has been done back & forth with no result found.

We're just looking for any result to mitigate the abysmal Vodafone-->2Degrees call quality and while we don't think this will help much, it can't make it any worse.

These are all personal devices among 3 people who just coincidentally happen to have /DS devices. 

Anyone got this working on a /DS device so as to contradict this theory? Or any other ideas?

(Edit; All testing done in Wellington CBD, (ironically?) about 100m from a 2D store.)