I belive this is OPs flight if anyone wants to compare plane data with ADS-B one. https://www.flightaware.com/live/flight/SWA2340/history/2023...
Conceivably, the ADS-B data source might be the same as the data source for this API, at least in that they might be calculated from the same instruments and flight systems.
So while I believe the data source is the same, one can see quantization artifacts when comparing both signals.