3G switch off my phone is compatible yet Smarty says it isn't

I also received an email on 31Jul24 saying my device may not work. I initially ignored it because I had already taken action following receipt of the previous email received on 10Jun24. My phone is set to use 4G where possible and preferred network is 4G/3G/2G. I also dialled *#*#4636#*#* to double-check, and found my phone was indeed VOLTE enabled. All good, so I thought. So, imagine how amazed, confused and angry I was when I did actually read the latest email and click the link to discover that my phone was listed as one that WON'T work after the switch off. So what to do next. New phone? or new MNO? Definitely feel the need to make a formal complaint. Having checked the Ofcom guidelines, they expect providers to let us know at least 3 months before the switch off if we will be affected, so we have time to make up our minds what we want to do, get a new phone or jump ship. The email on 31Jul24 was the first communication that I had which specifically identified my phone as one that will not work, and with the switch off happening in the first 2 weeks of September, I have not had the required 3 months notice.

I researched the issue further. It's the same with the other networks. Unless you have a premium-brand/ high- end ultra modern phone, or a phone purchased directly from them, it seems you may be affected. This has nothing to do with the phone being 4G VOLTE enabled or not, and everything to do with the network operator.

The technical reason they are referring to is the firmware that they control. Apparently it is a big job to support all the phones out there, so I guess the no-frills providers don't want to spend the money. They expect us to take action instead.

It would be helpful if SMARTY would publish a list of phones that WILL definitely work after the switch off. I'm concerned that jumping ship just lands me in the same place with the new network provider. I really don't want or need this hassle, especially with so little notice. And I don't want to buy a phone that is locked into a specific provider for 12/24/36 months. Definitely need a list of makes and models to choose from. Just saying it should be OK if it is 4G VOLTE/5G compatible and not on the list of tested devices is not enough. Murphy's Law says I'll find another phone not on the list of incompatible phones only to discover it still doesn't work, and was only excluded from the list because SMARTY haven't tested it yet.