Try two things:
Edit: Use Geolocator but make sure you have https enabled. See post from AbdiViklas below
If you have some kind of adblocker enabled or installed, try disabling it or uninstalling for the time being.
I was going crazy when my weather app stopped working all of the sudden even after I hadn’t changed anything and after performing step 1. Figured out that Ublock Origin was breaking it.