Can you provide a link to the HM 10 module that you have. A photograph? Many modules sold as HM 10 are copies/clones.
Consequently, there are several different modules sold as "HM 10" which have different firmware and requirements for the line endings for AT commands. I'm hoping that the lack of AT > OK is a line ending issue.
Issues around the AT communications may or may not be related to the lack of communication with the phone when connected.