Have you tried disabling the Power Save option altogether? Couple of other things you can disable are Google Now and under Advanced WiFi settings, change "Keep WiFi on during sleep" from Always to Never as it was before.
Also, before doing a Hard Reset, have you tried a full cache wipe?
By hard reset I should have stated "factory reset"... which I did and after all the aggravation associated with restoring my personal settings, aps, and info, this does not fix the Google Maps/Nav issue... actually seems to have made it worse. I will say some of the other issues reported did go away but Maps is worse.
I have not tried a repair center yet but doubt there is anything they can do other than give you a new phone that does not have the PoS Jelly Bean update on it, which is a disaster.
I had been a Window Mobile user forever and finally made the leap to Android... was really impressed, until now. The lack of knowledge and response to a significant programming bug is appalling. I guess I am going all the way to dark side and swap to an Iphone… since Sprint does not offer Windows phones any longer.