Phantom braking when GPS and Google Maps have a problem

This YouTube is from a Std Rng Plus Model 3 with 2020.8.1 documenting a GPS-vs-Google Map, 'phantom brake' event. It merges video of the screen, SAE units, and a ScanMyTesla graph in Standard Units:

• "SPACE" - toggles run and pause
• "," - backs up one frame at a time
• "." - forwards one frame at a time
• YouTube allows changing the playback speed

Chronolgy:

• Initially speed 63 mph (100 kph) with GPS reported speed of 50 mph (80 kph)
• seconds 3 - the graph shows up just as the GPS vs Google Map error suddenly drops speed to 40 mph (64 kph)
• seconds 4 - the car rapidly starts to decelerate to 40 mph (64 kph) BUT before leaving the 63 mph (100 kh) speed, Google Map redisplays the original 50 mph (80 kph). The car continues to decelerate.
• seconds 9 - the car has reached 40 mph (64 kph)

Bob Wilson