Right click on an event, select Event Details and compare event with ACT, RTN vs. "blank". You can see that the latter (Event Type: Condition Event vs. Simple Event) lacks event attribute "Alarm State". This is probably the reason of your problem, when a filter is set for a non-existing attribute, event is excluded from results. You can work around this by adding Alarm State attribute to respective Alarm Collection Definition in Library Structure. Look for "Event Attributes Definitions" in 3BSE037410-600_B_en_System_800xA_6.0_Administration_and_Security.pdf.