I think I saw this once before and determined it was an issue w/ the SDP-40 and its corresponding Crestron module...I think JBL directed me to a beta (at the time) firmware update but we may have also modified the module? Sorry, room was low-use, so we didn't get regular feedback and I changed jobs soon after, but maybe this will give you a place to look.

Does the CP2E control anything else that would help you determine if its the problem?