Sadly this phone turned out to be barely usable on my VoLTE network: when someone whose number I have in phone contact list calls, the phone displays number only and no name unless I turn off VoLTE, thus degrading voice quality and reception. Also the UX is generally bad. It is nowhere near the good old Nokia days.
I had a Nokia flip phone running kaios a few years ago. Kaios was the worst phone software I've ever run. The Nokia hardware was even worse. More often than not, keypresses wouldn't register at all or would act like you'd pressed the button four times.