Help me find this TV series

Hello Reddit I need help finding a TV series I watched around 2019. I remember it's about a man who lost his son in a car crash whwre he was with his wife, he works in FBI or Police I'm not sure. But when he goes to sleep he awake in another reality where his wife is death but his son it's alive. He has to solve the mystery of the car crash while living in both realities. Thank you so much.