The only fix to IMSI catchers/Stingray tracking of your cell phone is to not have your phone with you anywhere you don't want to be tracked. (or truly, get a burner phone you never turn on at home and paid cash for... very difficult to do).
@ai6yr Before we can even discuss phone tracking countermeasures, we have to understand the threat and the requirements. Having something with you in case of an emergency? Probably fine to just keep your normal phone, turned off before leaving the house. Maybe, if you want to be fancy, put it in a faraday bag.
Supporting a covert communications network that protects the users' identities? Much harder, and burner phones are only the start. Even the CIA finds it hard. See https://www.youtube.com/watch?v=BwGsr3SzCZc