iPad Pro & Consumer Cellular

Is anyone successfully using iPad Pro with Consumer Cellular? I had an iPad on my account and upgraded to Pro. Now the AT&T SIM card is recognized and connected, but I repeatedly get a message saying that there is no data plan (I have an unlimited data plan). Spent two hours on the phone with CC last night but they were unable to figure anything out. Then contacted Apple support and got a very nice service rep who was happy to cut and paste information that I’d read through much earlier but evidently was not configured for original thought. Any assistance greatly appreciated!