In UIM 20.4 the probe column in the alarm viewer has a SORT option. The issue is that this Probe column SORT option switches to the old alarm filter option (Similar to UIM 20.3) after entering Alarm Viewer few times.
Normally it looks like this (working as expected)
When the issue occurs, it looks like this.
Release : UIM 20.4 / 20.4 CU1
Component : UIM OPERATOR CONSOLE - ALARM VIEWER
This issue is no longer observed in UIM 20.4 CU2