If I am a woman, shouldn't it be मैं आज जा रही हूँ । ?
Correct. We have to report it. Remember, this is in beta, so they need to work out the kinks, which makes us reporting these things crucial, so they can make corrections and it can graduate beta!!!
I am a woman, so I wrote "मैं आज जा रही हूँ " yet it was marked incorrect. This is not incorrect. Both genders should be acceptable here. Silly!!! I know it's in beta, but it needs to be said.
Why this is incorrect?
मैं आज आ रहा हूँ
Because you wrote "I am coming today". You were supposed to write, "मैं आज जा रहा हूँ" (I am going today)