If you have a case on your iPhone or iPad, it may be obstructing the iOS connector from being inserted into the jack all the way. Please remove the case or cover to verify if this is the cause.

If you do not have a case or cover on your iPhone or iPad and the cable won’t stay connected, then there may be a problem with the iPhone or iPad, the Apogee product, or the cable. Please contact the Apogee Support Department to further troubleshoot the issue.

http://www.apogeedigital.com/support/contact-support