Agent Presence Histories table not creating records when agents go into "Available" state

Agent Presence Histories table not creating records when agents go into "Available" state, it only records when Away or Offline.

Logs show below error:

JavaScript evaluation error on:
(function executeRule(current, previous /*null when async*/) {

var agent = current.getValue('agent');
var presence = current.getValue('current_presence_state');
var channels = [];
var gr = new GlideRecord('awa_agent_channel_availability');
gr.addQuery('agent', agent);
gr.addQuery('presence_state', presence);
gr.addQuery('available', true);
gr.query();
while(gr.next()) {
if(channels.indexOf(gr.getValue('service_channel')) == -1) {
channels.push(gr.getValue('service_channel'));
}
}
var grHistory = new GlideRecord('awa_agent_presence_history');
grHistory.initialize();
grHistory.setValue('agent', agent);
grHistory.setValue('presence_state', presence);
grHistory.setValue('available_channels', channels);
grHistory.insert();

})(current, previous);
Root cause of JavaScriptException: java.lang.NullPointerException
: java.lang.NullPointerException:

All supported

awa_agent_channel_availability table contains records where the "Service Channel" column is empty. This column should always contain a value that corresponds to one of the Service Channels.

- Navigate to https://instance_name.service-now.com/awa_agent_channel_availability_list.do?sysparm_query=service_channel%3DNULL&sysparm_view=
- Remove these records

Once completed, you can remove the filters from the list and you will see that the remaining records have a value on the Service Channel column and Agent Presence history will be populated correctly.