Volte Not Working

[Ayam07]

Hi guys, i'm using MI5 64GB with MIUI EU 7.4.6

I have a problem that option for VoLTE is grey out
I can't turn the toggle on/off... Before this i don;t have this problem
The problem just appear after i do clean install
Anyone have idea what is wrong?? How to fix it??

 

[lsl640]

Same here, i asked the same question few day before but no 1 respond to it