iPhone won't connect to wifi, "incorrect password"

iPhone 5, running iOS 8.X, connects just fine at home and school networks, but never when traveling abroad and using wifi spots in hotels, airports, cafe's, Air BnB apartments, etc. I've read the thousands of forum posts recommending changing router settings to find a solution. This is completely useless if you're traveling and can't control or manipulate router settings to public wifi spots. Does anyone have a solution that is DEVICE SPECIFIC and not router dependent? Went to an Apple Store in Zurich this morning and after doing a factory reset, they told me get a new phone. Please do not post replies about changing router settings. Thanks.