One of 2 things most likely.
Don't chip if your first bounce is not on the green. People say 1 yard, but I don't think of it that way. As long as that first bounce clears everything it should be fine.
Or you're trying to chip at say less than 70% power or so, another no no. Only other thing that may be a problem is hitting the mark. Noticed that if you're off the mark by a good margin with chipping that could also give you problems. Hope that helps.