Something is definitely off here. Is the other iPhone running on our network as well? I'm assuming both of the speed tests were taken at the same location, right? Also, to answer your question, no, Band 71 is not available in the area as of yet. I'm wondering if your co-worker would allow you to put your SIM in their phone to run a speed test to see what the outcome is. I'm curious if yours will still be slower on their phone or if the results will remain the same.