Go to the hamburger menu, find the place where you choose your location on a map. Zoom out and select a location in a completely different continent. Go for South America or Africa if you have to. Then save and go back and this time select the proper location. That should reset your location and maybe get CoRE to work. If that does not fix it, try installing webCoRE (still beta), it’s the next gen CoRE and you probably won’t regret it.