I figured out how to get an LTE data connection using a Rogers SIM card in the PCM so I thought I would share the information.
If you use a Rogers SIM for data in your PCM, you may find that you are only getting a 3G connection. To enable LTE, do the following: (I think this applies to all Porsche car with the latest PCM, not just 911, although I tested it in my 991.2 C4S)
1. Go to Phone. Press the Opt button. Choose SET PHONE, Data connections, Configure APN.
2. Set the APN to be ltemobile.apn. No need to change the user or password.
3. Exit the settings.
You may have to wait up to 10 mins but eventually, the data connection will change to LTE.