Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N77571 - Boeing 737MAX 9 - United Airlines UAL3932/UA3932, Chicago O'Hare (ORD) to Austin-Bergstrom (AUS) - 5.1 mi away @ 38400 ft, heading SW at 458 mph. Spotted 4x before! [02:38:50 PM CST] #AA7F01 #N77571 #B39M #UNITED #UAL3932 #UA3932 #ADSB #ADSBbot