First and foremost, Google tells users to hard reboot the device before trying any other workaround. Hard rebooting doesn’t delete any of your data, but it does clear the memory of the device, so essentially, Waze would have to load from scratch the next time you launch it. This forces the app to reinitialize the connection to the GPS, but at the same time, also reset the sensor on your device.
The methods to hard reboot a device are different from one brand to another. On the iPhone 11 Pro, for example, you need to press and quickly release the volume button, then do the same for the volume down button. Next, press and hold the side button and wait until the Apple logo appears to release it.
On Android, it should be enough to just hold down the power button until the system completely reboots. This typically takes anywhere between 10 and 30 seconds, so just keep holding until you see the device restarting.
If the error message doesn’t go away, the next step is to determine if the GPS sensor on your phone is working correctly. Google recommends downloading a “GPS status” app from the Google Play Store (or App Store) and check if the accuracy is 0 meters (0 ft) or over 35 meters (115 ft). If this is the case, then the GPS sensor isn’t working correctly, and your only option is to reach out to the manufacturer of the phone for a fix or a new software update.
If the GPS accuracy is under the second value, then everything is working correctly and what you need to do is reset the calibration using a dedicated app in this regard (most often, the GPS apps that are published in the Google Play Store and indicate the accuracy can also help you with this).
Eventually, if the error message just doesn’t go away, then reach out to Google because Waze could be the app that might need a fix.