Data Connection - Phone Call - Text Message Issues - Help

Hello. I wanted to see if anyone could provide some advice.

My family member and I are on the same T-Mobile plan.

They have a newer iPhone - I have a Samsung.

We live in different homes.

Below are some of the issues we are having. These issues occur when we are home and we are out running errands etc.

Phone Call Issues

When trying to make a call out:

• Its dead air for a few seconds and goes directly to voicemail or rings once and goes to voicemail ( Happens intermittently )
• Some calls will go through, some wont. It doesn't matter what type of service the person has that we are trying to call or what type of device they have ( Happens intermittently )
• Who ever calls us goes directly to voicemail without any notification that we missed a phone call. ( Happens intermittently )

Text Issues

• Some text messages we try to send wont send at all ( Happens intermittently )
• When others send texts to us, we often don't receive them or they are delayed and it takes hours before we receive them ( Happens intermittently )

Connection In General

• Any and all apps have a hard time loading ( Happens intermittently )
• Any and all apps malfunction. They close with errors or freeze. ( Happens intermittently )
• Messaging/video chat apps wont function properly ( Happens intermittently )

Performed Troubleshooting

• Restarted devices
• Disabled Wi-Fi
• Disabled Wi-Fi Calling
• Disabled Bluetooth
• Disabled and Enabled data connection
• Double checked any settings that could have been interfering with our connection
• Uninstalled any newly installed apps
• Double checked our Network Mode is set to the correct settings
• On the Samsung I did notice that the SIM card status for "Mobile Network State" says "Disconnected" (I'm not sure if that is important)
• Both devices are updated to the most current software

The iPhone has been having this issue for the past month and a half

The Samsung has been having these issues for over a year

I have contacted tech support about the Samsung and they fixed something and the issues seemed to improve but over time the issues started back up and became worse.

They did not disclose what they fixed or what to do in the event of the issues coming back

I'm not sure what to do or what could be causing the issues. Any advice would be greatly appreciated.

Gracias.