Resolution: One cause of this is improper setting of GLOBAL_ID in SERVER_NAMES to same value in multiple database. In this case the EADs of all of those servers will act as a Fault Tolerant group and only one EAD will be actively looking for triggers in the database. The incorrect setting will arise often if database is copied from Development to UAT for example. The GLOBAL_ID will have to updated after copy to avoid having an active Fault Tolerant group for the EAD, Notifier and Sleep Agent.
Note, if you have added additional servers to a single database you will see an additional entry in that single database in SERVER_NAMES for the additional server. It will have the same GLOBAL_ID and in fact must have the same GLOBAL_ID.