Arlo Doorbell (wireless) unable to pick call or broadcast audit in 4G

[Kuang]

Model: AVD2001B-100AUS, purchased from Bunnings warehouse 

App: Arlo 3.2.2 (2422)

Platform: iOS 14.6 (tested on iPhone X, iPad Pro and iPhone 11 max)

Issue: 

• Unable to pick up call from door bell after pressed under 4G network (Telstra). The call drops out after about 10 seconds of blank screen. The feature was previously working fine. 
• Unable to broadcast audio in App under 4G network. This works fine if mobile is connected to home Wi-Fi. 

Tried: 

• Reset Arlo Doorbell, re-pairing to App. Not solve the issue.   
• Delete Arlo app, re-install app. Not solve the issue.

Due to the issues above, the doorbell turns into entirely useless.

Please help. Thanks!

[JamesC]

Kuang,

Is this an intermittent issue or does it happen every time you receive a call from the doorbell?

JamesC