Unsaved activity

Good morning, on 28.03.20 I performed a session of 1h20 'and after finishing I saved correctly as I always have. Now in my activities the file seems damaged, it does not show data and it only brings 30 'of activity. what should be done?

Nothing really. You cannot manually upload.fit files to Zwift and Zwift Support does not have any mechanism to insert .fit file into there data base.