Microsoft teams direct routing incoming calls dropping at 30 seconds

We are using Microsoft Teams direct routing carrier model.

Outgoing calls are working as expected with no issues at all.

The problem is incoming calls are dropping exactly at 30 seconds .

Explanation : When an incoming call comes to Microsoft Teams cloud , it gives 180 ringing multiple times the problem is in these 180 ringings "TO"  tag is different, de to which our operator is getting confused and not replying with Acknowledgement.  The operator does not support 180 ringing so he is expecting either a single 180 ringing or even if multiple 180 ringings are there then the TAG should be same.