Normally, I should receive an SMS notification from my carrier about any missed calls if my iPhone or the network is offline. I don't receive them on my personal iPhone, but I receive them on my business iPhone. (Same carrier.)
I spoke with my carrier and they told me that this service is active for my number on their side so there is a setting in my phone which overwrites it. But they don't know where can I set this up.
I Googled a lot about it, but can't find the solution.
Can anybody point me in the right direction to find where this setting is?
Model: iPhone 8 iOs: 15.4.1