Starting with version 4.0, the trigger overview view on both the overview page and dashboard widget has a quirk where it refuses to show all of the OK triggers if there are any in Problem status. I do also note that this causes a large overview to load way faster when there are some Problems to show so it may be intended or a regression from enhancing the overview query.

I don't have any experience with PHP but I've tracked it down to these lines in include/triggers.inc.php inside the function getTriggersWithActualSeverity

$triggerids = zbx_objectValues($problems, 'objectid');
$triggers = array_intersect_key($triggers, array_fill_keys($triggerids, ''));

This seems to have a side effect of always filtering out triggers in OK status that match no $problems. I have edited this to confirm that this is where the issue is and also added a threshold value to make grids of over 300 items load quickly and show only the Problems:

if (count($triggers) > 300) {
$triggerids = zbx_objectValues($problems, 'objectid');
$triggers = array_intersect_key($triggers, array_fill_keys($triggerids, ''));
}

So now our modest size grid of a group of 7 servers will mix loading OK and Problem values, but our larger grid of SNMP data from 24-port Cisco devices will either be all OK or just the Problems loaded quickly.

I wanted to submit this to either confirm the behavior is intentional or point out where the patch needs to be focused.