My apple 5s is no longer getting 4 bars in same location it did last week. It varies between 1 bar and no service. Noticed it for the first time over the weekend. Sitting beside my iPad which reads 4 bars, the 5s has 1. Zip code 22802.
I'd like to know it anyone has any insight to this as well. While my signal rarely gets as low as what you're experiencing, it does fluctuate a bit from my iPad Air to my iP6+. For some reason my iPad Air always has a better signal than my iPhone with both of them in the exact location...