LTE+ Missing or Slow on new iPhone 11 Pro Max dual SIM

Hey there AdamKPL,

Thanks for reaching out to Apple Support Communities. I understand you’re experiencing some issues with your cellular data. I’ll be happy to help with this.

If you’re cellular data seems slow, there are a few things you can try that may help:

1 Make sure that you're in an area with cellular network coverage.

2 Restart your iPhone: Restart your iPhone 

3 Check for a carrier settings update: Update your carrier settings on your iPhone or iPad

4 Update to the latest iOS: Update your iPhone, iPad, or iPod touch 

5 Reset your Network Settings in Settings > General > Reset. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.

If that doesn’t help, review this info:

“Your device can also seem slow as it repeatedly reconnects to new cell towers when you're in a moving vehicle.

Even if your device indicates a strong signal, you might need to wait, try again in a different location, or use available Wi-Fi. If you continue to experience issues with cellular data speed, availability, or performance in multiple locations, contact your carrier.” You can read more about this here:

About iOS performance on your iPhone, iPad, or iPod touch

That being said, you find some helpful info on how you can change which data plan you’re using here if you need:

Using Dual SIM with an eSIM

Take care.