CarPlay GPS showing incorrect speed and beeping on iPhone

After months of CarPlay GPS working smoothly, suddenly I’m experiencing all the issues mentioned here by others plus the mph is totally messed up. I’m doing 5 mph and it’s beeping away at me that I’m doing 170 mph!!!! Nothing has changed: same phone, same connection method, and I’m current on all updates. Very frustrating!

[Re-Titled by Moderator]

Original Title: Wonky GPS Navigation