I came back after a few months of not playing. Can no longer summon my sparrow, Tried deleting the Cvars.xml to see if the key mapping would restore itself, did not work, there isn't even a summon sparrow bind key option in the controllers settings, it's like If I had started a game from scratch, but I've put 200 hours into my character.
Hey there!
When you are on a destination and pull out your Ghost, it should show you the assigned button for summoning your Sparrow in the bottom left.
For me, it is E as the standard.
Could you try to check what is shown for you when pulling out your Ghost?