Yes it still shows as 3G and it is no longer active.When I first activated the service in the fall of 2018 the car reported 3G. I thought it weird as JLR had listed it as LTE compatible. After a month or two it changed to 4G. Does yours still show as 3G on the screen?
The Jaguar remote app still connects and is receiving data.Does the Jaguar Remote app connect and get recent data about the car?
Do you have a SIM in the center console slot that is not original to the car?
You may need to have the TCU replaced if the car is a very early build.
I have a sense that this may be an acct issue at AT&T. My traffic updates were working fine while driving down to Durhan NC on Fed 28th, but on the way back Mar 2nd I noticed I had no connection. My acct would renew on the first of the month, whereas I believe the 3G towers were turned off earlier in Feb.The hardware has to be 4G capable too. The really early cars did have some hardware issues that later builds did not experience.
It would have been quite a misstep by Jaguar (or AT&T) to provide SIM cards that were limited to 3G capable. It might be worth a try to get a AT&T store to at least test the possibility.