Actually this only happens if the window is minimised. For example if several KAlarm alarms go off, and you minimise them rather than cancel them, and then one of them recurs. Then there is an inconsistency, because the group visibly signals that it is calling attention, but the individual alarm window doesn't.

A perfectly good workaround is to right-click the group and do 'restore all', then see which in the list is flashing and deal with them, then right-click the group and do 'minimise all'. But people may not think of that, perhaps assuming that restoring would cancel the 'calling attention' state (it doesn't), and if you don't think of this workaround then it's really difficult to deal with.

It is useful that the group calls attention, and a single minimised alarm still calls attention (easy to test with an alarm that recurs every minute), so minimised entries in a group of windows should too.