Hello!
I would like to know if it is possible to re-import an activity from Garmin Connect. The barometer sensor from my Garmin Edge 530 is working incorrectly and I would like to import the activity once I have fixed the altitude in Garmin Connect. Is there a way of doing it apart from deleting the activity in Intervals and re-importing the FIT file?
Thanks! 
A fix on Garmin Connect isn’t modifying the FIT file. So that’s not going to help you because you can’t get the corrected elevation.
Did you try the elevation correction in Intervals?
Yes, I tried. It does not modify the elevation profile, only the climbing figure, normally adding a huge amount of meters which is also not correct.
It does, but you must display ‘Fixed Alt’.
If the climbing field is not correct either, then this will not work well though. Unless the discrepancy is caused by a single starting point, which can easily be corrected on the Actions-Fix data menu.
The elevation in the Fix-Alt graph seems correct, but the Climbing number is way off (for comparison Garmin Connect after fixing elevation shows 1100m while Intervals show 1700).
I have tried the fix altitude action but it does not change anything.
Yeah. The fix can be iffy. But that’s the issue w elevation. It’s really not a simple calculation and I bet GC (and Strava) has their own way of calculating all the gains and losses.
But you should still be able to edit the final number. I believe that has been enabled
Totally, I can see that the elevation correction between GC and Strava also has a big difference. I guess it depends a lot in the calculation and the elevation profile you take as base (some are smoother than others).
I will fix the altitude and then change manually the climbing number taking the one that makes more sense to me (GC or Strava). I guess the final solution is to buy a new bike computer. 
Thanks both for your help!!