This cell phone issue started within the past 2 months on this iPhone 6 plus and also happens on Galaxy 7 and basic keyboard LG cell phone under the same Verizon Account. SnapChat on the iPhone 6 Plus was uninstalled. The settings on the iPhone 6 Plus were checked and the Network Settings were reset by the Verizon store tech and problem still exists. The call in the video was from the iPhone 6 Plus cell phone to the house phone. The house also has a verizon network extender. This issue occurred in this test video on an outgoing call from the cell phone to the comcast land line home phone in Salem NH. However soon after this issue happened after approx 3 mins from and incoming call from islip NY to Salem NH.
See video
This video shows that after approx 2.5 minutes there is 3 quick beeps and shows "Call Ended"
Upgrading the iPhone iOS to iOS 12.0 with carrier network updates helped but issue still occurred at approx 4 minutes duration instead of 2.5 mins when calling from cell phone to home phone at home. When calling from the verizon store to home we surpassed the 4 mins so the issue points to the 3G network extender in the user's home. After disconnecting the network extender, the call went 10 mins without dropping!
The 3G network extender now causing the issue is:
Verizon Wireless Network Extender
Model SCS-2U01
Rating 12 v 1.5 A
51Y7
E149091
I.T.E.
Removing this from the comcast modem resolved the problem
Also there is an updated 4G network extender that may resolve the issue but the cell phones must also be compatible with 4G
