Atom git-diff is not working in mac machine -

i using atom in mac. whenever press alt+g up/down inserts © symbol rather showing next diff. there doing wrong?

pressing alt+g on mac inserts © symbol.

pressing alt+g in atom on mac delays insertion of © symbol second. if hit ▲ or ▼ key during time, insertion of © symbol prevented, , cursor jumps previous or next diff in file.

it's matter of timing.