I've used EchoAccess to change custom properties of an Echo Room Controller (ERMC), but it isn't responding to those changes. One example is assigning two relays to the same Echo zone, however, only one relay responds when you try to control it using presets or zone control.
Explanation of Issue & Fix
The ERMC is responding this way because it has not been switched to operate in custom mode. Just above the space/zone wheels you'll find a small yellow switch that allows you to change the mode of operation between Basic and Custom. Push that switch up to change it to Custom and test functionality.