If your signal keeps fluctuating and you never receive

 

incoming calls, that means your iPhone is losing connection to the carrier network repeatedly.
This is usually caused by one of four things:

1. Carrier settings got corrupted (common after failed profiles/apps)

2. SIM issue (physical SIM or eSIM glitch)

3. Network profile installed by the new app

4. Hardware antenna issue (less common unless the phone was dropped or got wet)

1. Turn Airplane Mode ON → wait 10 seconds → OFF

This forces a fresh connection to the nearest tower.

Swipe down from the top right → airplane icon → ON
Wait 10 seconds → OFF

Check if signal stabilizes.

2. Important: Reset Network Settings

If calls don’t even appear, this is the most effective software fix.

Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings

This refreshes:

• Cellular configuration

• Carrier settings

• eSIM/SIM network handshake

After your phone restarts, wait 1–2 minutes for the signal to settle.

3. If you use a physical SIM: Reseat it

(Only if your iPhone model has a SIM tray — newer US iPhones are eSIM only.)

1. Power off your iPhone

2. Remove the SIM

3. Clean it gently

4. Reinsert

5. Turn the phone on

If the signal becomes stable afterward → this was the issue.

4. Check for ANY installed profiles or VPN (common cause)

Go to:
Settings → General → VPN & Device Management

Look for:

• Any Configuration Profile

• Any new VPN that is ON

If you see anything related to the new app/email:
→ Remove Profile
→ Reboot

This often instantly restores normal calling behavior.

5. Carrier Settings Update Check

Go to:
Settings → General → About
Stay on the screen for ~10 seconds.
If a popup appears saying Carrier Settings Update, tap Update.