Actually, the translation software is correct — this time. Explanation: We do not use inversion in embedded questions, that is, subordinate clauses. Instead, we use normal subject verb statement word order (except for the question word itself, which is fronted): Question: When does the show start? Statement: The show starts at 8:00. Embedded question: I don’t know when the show starts.

Adding "do" changes the question. The original question is actually a shortened one. This is the original "I want to help you, but I do not understand what it is that you want to say." It also means "what are you trying to say?" Adding "do" makes it a command and it sounds (to me) like the speaker is angry and wants the listener to give an answer right away.