cant open door

my rear passenger side door cant be opened from the inside but can be opened on the outside. yes my child proof lock thing is off. my friend was able to get it open by first opening the inside latch once then one more time with a push and it opened… that method doesnt work all the time infact it doesnt work anymore. anyone have a clue what the problem is?

One of the rods came loose from either the latch or the indside handle. Remove the door panel and fix it.