Hi all,

pleasure to be here, I bought a used LG G5 because I needed a phone to connect via Tello (Sprint), long story short I was able to connect the phone with Tello but my issue is that if the phone is on LTE I cant make any calls/texts, I get an error message saying: Mobile network is unavailable but internet on LTE works fine. if I switch from LTE to CDMA (3G) I'm able to make phone calls/Texts but I'm not able to user the internet. Tello it's been working with me on this issue since December, I've been researching on this issue all over the internet with no luck. today tello called me and told me that the issue is on the phone and that I should take it to a repair shop, I'm not sure what the repair shop will do to fix this so that's why I'm here looking for your PRO help. any help is appreciated.

Model: LG G5 LGLS992
Android version: 7.0
Android Security Patch Level: February 1, 2018
Kernel version: 3.18.31
I have replaced the sim card
I have reset network settings
I have factory reset
I have reset the phone via root
I have update PRL
I have update Profile
I have update firmware
UICC unlock : Failed to update
Mobile data is on
Roaming is off
4G settings: Network operator: n.mi.ispsn
Network: LTE/CDMA
no VoLTE option on LG G5.
no Advanced Calling option on LG G5

Thank you so much