I have my Fitbit Aria scale connected to MyFitnessPal and to Garmin Connect. MyFitnessPal nutritional information syncs to Garmin Connect, however, my Aria scale syncs to MyFitnessPal but does not (it used to) sync over to Garmin Connect :mad:. I've combed the forums and it seems like it was an issue back in early 2016 (and before) but it seemed to be corrected. An earlier noted fix was to switch back to "classic mode" in Garmin Connect and delete an erroneous weight logged somewhere in the future (2029), however; I can no longer find "switch to classic mode" as an option (click the head on the left menu of Garmin Connect...) Any ideas?
There is no longer a classic mode available with Garmin Connect.
I had problems getting my weight to sync across from Fitbit to Garmin Connect when I was using a Fitbit One and a Fitbit Aria scale. I got around it by going to the Calories In/Out on Garmin Connect and forcing a sync. I had to do this daily as Garmin Connect would only pick up the most recent weigh-in.
I got it to work automatically by returning the Fitbit scale and buying a Withings scale and using the activity tracker feature of my Forerunner 230. When I set Garmin as my step source in MyFitnessPal it all started working automatically, even if the weight readings in Garmin Connect are on the wrong day (they are a day behind, but they are current).
If you are not using a Fitbit tracker, you could try setting Garmin Connect as your step source in MyFitnessPal and see if that works for you, even if you are not actually using a Garmin activity tracker.
I find that the data from my Withings scale can be used by a lot more other services then I could with the Fitbit scale.