Hey Roast68,
Thanks for using Apple Support Communities! I understand that GPS isn't working as expected on your device since updating the iOS. I certainly depend on GPS as well, so definitely understand the importance of getting this resolved.
To start, I recommend taking a look at the steps in the link below to ensure GPS is enabled and settings are correct.
Turn Location Services and GPS on or off on your iPhone, iPad, or iPod touch
If that's unhelpful, I would like to get a bit more information on what's happening, and we'll go from there.
What model iPhone and iOS version are you working with you? You can find the exact iOS version in Settings > General > About.
What exactly happens with GPS, are you seeing incorrect information or something else? Are you getting any errors?
You mentioned two specific apps that you're running into issue with GPS, are you experiencing GPS issues with other apps? For example, Maps?
Thanks again, and have a great day!