plugin stop sending out the customed shipping notification a few months ago

plugin works fine for the past year, but it stop sending out the costumed shipping notification email as it always does, a few months ago, instead of that, it sends out bunches of “tracking updated” emails (normally it only sends out once, if tracking status changes while under transit).

Your plugin is customed installed at the beginning from your team. Please check and help.

Attached those crazy amount of shipping status update emails which were sent out – almost every minute the plugin will send them out a crazy amount to different customers.