The trigger sets the alarm trigger level. unlike before, it now uses the blue sleep pattern graph as data source. This should give a more accurate alarm. If your blue bar is always too low, increase the value in the settings window. Actually it should already be on a good level, unless you changed it. I have it around 30..40. Changing this value will also impact the display of the already done records. Once you have set the blue bar, I suggest to set the trigger level around the top end of the grayish background bar, indicating "light sleep" in the graph.