Steps and calories

matt30in30

I have a question, sorry if it has already been asked but I did some searching and was unable to find anything.

I have my Garmin set to count my steps and sync to the app then I use Fiit for my workouts which uses a chest strap for heart rate and syncs directly to the app.

My question is at one minute the app says I burned 546 calories in steps from garmin then after I work out using Fiit and it syncs my calories to the app all of a sudden the calories I burned through my steps have dropped by sometimes more than 300 calories. Is this right ?