I have an older smartphone (Motorola Droid Bionic) which has always been able to receive 4G LTE service in the two places it is used the most (West Los Angeles and Palmdale CA). Approximately 4 days ago, the 4G LTE service stopped functioning in the Palmdale area, dropping down to 3G and even occasionally 1X. It has not recovered, not even temporarily after reboots. Full 4G LTE service continues to be available on this Droid Bionic in the West L.A. area, and 4G LTE service still seems to be available in Palmdale to other Verizon smartphones (e.g. iPhone X, etc). Has a specific change occurred to the 4G LTE service in the Palmdale area which would have caused this?