Iphone X Cellular data issue

i recently bought the Iphone X 2 weeks ago and today i keep getting a message saying "could not activate cellular data network, you are not subscribed to a data service" and "LTE calls turned off" however when i look at the top of my phone it shows i have 4 bars with LTE beside it. Ive tried a new sim card and every troubleshooting thing possible and still nothing is working.