Lose my data in garmin connect

What can I do to import the historical data?

Data remain in the Garmin Connect account regardless of the app version, so updating the app has no impact on the data. The data is stored on the server, not on the phone. If you do not see your previous activities on the app, then perhaps you are not logged into the same account as originally. Though if you tell you cannot upload old activites, a blank account would not mind, so your problem may be elsewhere.

What data exactly do you miss in your Garmin Connect app? Which screens? Can you post some screenshots demonstrating your problem?

Hi Trux,

thanks for replying,I agree with you. I'm sure my data are not erased or crashed, it's just a question of synchro but I don't know if I did the right manipulation. Here is the screen I had in my garmin connect app when I want to see my last year's activities : 

So I tried to import my old activities from a fit files I had.

I pasted you here below the screens of each step I've made to import the fit files on garmin connect app.

Step 1 : I had fit files from my account

Step 2 : Importing the fit files on garmin connect

Step 3 : message from garmin connect app but when I refresh my app, nothing changed.

Thanks very much. My data are indeed there on the web account but not on my app. It's quite weird because I put the same ID and password... 

Have you ever seen this kind of issue?

Be that as it may, thank for your time and answers.. 

Up and then there are people setting up inadvertently a new account when reinstalling GCM, and then wondering about the non-matching data. You can verify it easily by sharing an activity from GCM and another one from GCW. The true user id can be then seen, when opening the links in a browser.

Thanks very much for your help, your answer helps me a lottrux