Can't use AudioMix on iPhone 16 Pro Max with iOS 18.1.1 and VoiceOver

Today my brand new iPhone 16 Pro Max arrived in my hands; I immediately started using it and I wanted to test the brand new AudioMix feature.

After having ensured "Spatial Audio" is set in the recording settings, under Camera/Record sound, I opened the camera app, both using Camera control and normally by tapping the Icon. Recording the video in normal video mode, with any resolution including 4K/120FPS, in video edit screen, a part from the already known regulations, filters and improvements, I don't see any audio mix button in the bottom bar. I tried recording using cinema and it worked only the first time; for every recording I made after it, both in cinema mode and in normal mode, I never saw the audio mix option again.

I am using iOS 18.1.1 and VoiceOver is on, since I am totally blind.

My only followup is: is it happening to you as well? Could I fix it in someways or I do have to wait iOS 18.2 / install the RC? How are you finding Audio Mix?