ipad 3G function quit working after OS update to ios 9.03.1

Shortly after Apple updated the OS to iOS 9.3.1, my ipad 2's 3G functioning ceased to operate. I changed sims, & then it would work with the new sim but only until I powered down...when I power back up....the new sim also fails to operate...I get the "No Service" message! I know the sims are good as they work just fine in my hotspot unit! I see other folks are experiencing the same problem....any viable solutions yet to this problem? Thanks JoeMamaD