I wonder if the update causes the GPS chip to overheat and then malfunction. So, it might work for a brief period after a hard start, but then the chip overheats and malfunctions. My Waze app shows a status message "No GPS. Showing approximate location." My Fitbit mapping app shows "Poor GPS Alert. Continuing with tracking court result in irregular GPS data for this activity" (hence a 3.5 mile walk is recorded as 6 miles).
The iOS7 upgrade for some 4s phones caused permanent damage to the WIFI chip, which also disabled the Bluetooth connectivity. If the iOS 9.1 update caused permanent damage to the GPS function, then subsequently issued patch is not going to restore the function on the broken phones.
I called Apple support on Nov. 11th to seek a fix. Got transferred to a senior support agent. That senior support tech submitted the information to the engineers and was supposed to get back to me Monday. She called back on Sunday instead, when I had told her that I was not going to be available on Sunday. When I tried to reach her on Monday, I got assigned to an new senior support agent, who asked me to downgrade back to 9.1 (I had installed 9.2 beta 3) and send screen shots of what the mapping apps were showing, which he was going to send to the engineers. I sent screen shots in the morning, but he had not sent them to the engineers yet. Now I have to wait until next Monday to hear the engineers' verdict.
I asked the support agent about possible remedies, since my phone went out of warranty in September. Assuming the engineers can't restore the GPS (I have done a new install of 9.1 and everything that is supposed to be on is on, so I really doubt it is a software issue), and they don't "verify" a hardware problem (notwithstanding how it was caused), am I out of luck? I don't expect an upgraded replacement (such as a 6s), and would okay with paying something like $150 for a refurbished replacement iPhone 6, but I don't like the option of paying $299 (although, I guess I might, since I am dependent on the GPS apps), or worse, will I have to purchase a new phone for full price.