If there are more than 500 faults in the visible part of the timeline for the displayed object, alerts are not shown in detail for the object, and the background color becomes pink.

Faults are calculated for a range of intervals, not for each interval. In the case shown, they are counted for ten columns from 3:30 PM to 6:00 PM and for one column from 6:00 PM to 6:15 PM. Even if the maximum number of faults is exceeded only in three columns, all ten columns will become pink.