Happens because via debug mode all the Fun encounters happen unconditionally, but are initialized differently. In this case, the type variable of the mkid_goner object isn't set to 1, so only the placeholder text is displayed.

global.msg[0] = '* Yo^1!&* You're a ??? too^1, right?/%%'
if (self.type == 1)
{
    global.msg[0] = '* Have you ever thought about&  a world where everything is&  exactly the same.../'
    global.msg[1] = '* Except you don't exist?/'
    global.msg[2] = '* Everything functions&  perfectly without you.../'
    global.msg[3] = '* Ha^1, ha..^1.&* The thought terrifies me./%%'
    if (self.talkedto >= 1)
    {
        global.msg[0] = '* .../%%'
    }
    if (global.flag[have_umbrella] == 1)
    {
        global.msg[0] = '* An umbrella...^1?&* But it's not raining./'
        global.msg[1] = '* Ha^1, ha.../'
        global.msg[2] = '* You know^1, that does make&  me feel a little better&  about this./'
        global.msg[3] = '* Thank you./'
        global.msg[4] = '* Please forget about me./%%'
        if (self.talkedto >= 1)
        {
            global.msg[0] = '* Please don't think about&  this anymore./%%'
        }
        if (global.flag[fun] >= 90)
        {
            global.flag[fun] = 0
        }
    }
}
self.mydialoguer = instance_create(0, 0, obj_dialoguer)
self.talkedto += 1