I may be wrong, but I thought prompting for information didn't function on the mobile portal. Is it possible that your co workers could use the service portal instead?
I am just in the process of setting up the mobile portal and have the same issue. I have a query that prompts for the incident reference number. On the mobile device the prompt appears but no matter what you enter all the incidents are listed. Is this just a buggy product in general? This is LanDesk 7.3.1