You might have a TCP/IP Console Event Detector (e.g. used to run an NCL) and an alert is NOT to be issued for it. If on the ED's section Create Alert field Severity is nonzero and field Alert Type is set to AO (ACTIONONLY) when this is saved Alert Type will revert...
Customizer (shortcut /PARMS) group $ AM ALERTS includes field Alert Exit Name. F1=Help shows the alert exit sample as being found at high-level-qualifier.MSSAMP( $ AMALEXT). However (for NetMaster r12.1) the alert exit sample can be found at high-level-qualifier ...