In December, I got a forerunner 965. Now my garmin connect account has lost all historical runs, weight, and activity. Is there a way to show all data in my dashboards?
You probably created a new account instead of reusing the old one. Remove the new watch from Garmin Connect app, web, and Garmin Express, sign out from all Garmin apps, then sign back in with the old credentials, and add the new watch to the old account in the Garmin Connect app.