While Google's recommendations might get Google Maps fully working again for some, there is obviously a chance they won't make any difference, in which case you should try something else.
If you are sure that the latest version of Google Maps has broken down the navigation for you, the easiest way to fix it is to simply downgrade. To do this, you can get the standalone APK installer from this page and then manually revert to the previous version of Google Maps.
On the other hand, if Google Maps has GPS issues, you need to make sure that your phone's GPS sensor is working properly. Go to the Google Play Store and download a GPS information tool to verify sensor calibration. Alternatively, you can also try another navigation app, like Waze, and see if it can tell you where you are and then follow you on the map.
If you are in the beta program for Google Maps and have problems, you should try to downgrade to the stable version. Beta versions obviously come with a higher probability of problems, as their purpose is to help test new features and gather feedback before a specific update is activated for production devices, and it is not recommended to install them on the main phone.
Instead, you should always test a beta version of Google Maps on a secondary Android device that is not used for critical things.
And last but not least, if Google Maps is not working properly, check that the internet connection is working properly. Alternatively, you should also download offline maps on Google Maps using a Wi-Fi connection and then see if the navigation function is back to normal. In fact, this should also help you determine if your phone's GPS sensor is working properly.