 If you accidentally delete a Strava activity you can always re-upload it from Garmin Connect using the web browser on your phone rather than the app. Log in and go to Activities. Click All Activities and then choose the activity you need. Click on the cog and then click Export Original. Then click to download and open it in Downloads. Tap on the file to unzip it so you've got a fit file. Then open up a new browser tab and log in to Strava. Once logged in click on the hamburger menu at the top and scroll down to the bottom and click on where it says Upload Activity. Click File and choose Files. You may need to search for it but choose the correct fit file and it will upload to Strava automatically. You can give it a name and then click Save and View. And there's your activity back up on Strava.