Incoming/ Outgoing call problem while on 4G network with no volte support.

[bukupuku]

I have recently bought the MI A1. While buying itself it was updated to the latest may patch.
The problem is while on 4g network, I cannot receive nor make any phone calls. For calling I have to manually switch to 3g/2g mode from *#*#4636#*#* menu. Is this a normal behavior of this phone as my other phone swiches to 3g while incoming/ outgoing calls and back switches to 4g after the call is finished.
PS: my network doesn't support volte. Phone is manufactured on Feb 2018, it's not modified by any means.

 

[JockeSve]

That's not normal behavior.
I've never seen a phone where You have to switch between 3G/4G/LTE for calls and data.
Can You try a SIM-card from another service provider to see if it behaves differently?
If You check at https://willmyphonework.net/ are all bands supported with Your provider?

Or, in worst case of course, try a factory reset and see if that makes any difference...

 

[.:Addicted:.]

Set to 3g/4g in *#*#4636#*#* menu.
Airtel doesn't support volte in all circles yet. Only rolled in few circles. In 3g/4g mode, it'll be mostly in 4g mode if nw strength is good & switch to 3g when you call or receive a call