ZB630KL has serious issue with Vodafone volte, all of my Vodafone sims work fine with my Nokia 6.1 but none works with my max mro m2. Whenever I put Vodafone sim into my max pro m2 the 'use enhanced 4g volte' option under network settings is not there. Tried factory reset, same problem. Two of my friends have m2 and they face the same problem. I have wasted my money on this phone. Never going to buy another Asus phone in future.
Volte functionality depends on the operator to test and validate for us, which far from all of them have. Even bigger operators. We are of course doing our best to get their help but it's a long process.