However, don’t assume that the problem is the channel just because it is a switch. For my Aeotec trisensors, that motion alarm switch is the correct motion sensing channel. It actually makes sense as a writable switch instead of just a readable contact item because as an “alarm” you might want to be able to deactivate/reset it prior to the automatic timeout reset time (i.e., something just triggered motion on the back yard sensor, oh it was just a bird flying by, I can turn that back off again). More likely the problem is the configuration of the device’s parameters. Without knowing more details about what the device is, what system you’re using, what you’ve tried, and what the logs say, we can’t narrow that down for you.
Double check that the controller is included in the proper association groups. Occasionally, devices will also provide a configuration parameter for enabling/disabling reports for COMMAND_CLASS_ALARM.