I have a Garmin Forerunner 945. When record a swim with HRM-SWIM the activity is recorded on watch with external heart rate data, however, it does not get synced to Garmin connect. I tried to upload the activity manually from my computer via .fit file on watch.
When try to upload to Garmin Connect get the error message "We don't support the file type you tried to import.".
When try to upload to Strava I get the message error message "The upload appears to be malformed and we are unable to process it."
In the past if I don't use HRM-SWIM external heart rate, activity uploads normally.
Is there a problem with HRM-SWIM or is there a bug in recognizing the heart rate data from external device?