Strange Issue - Last MIDI Drum Note Is Low

Normally the length of triggered drum notes shouldn't make any difference but it's worth checking to see if this last kick is the same length as all the others.
 
If it is, maybe it just sounds quieter because it's decay is being chopped off. Try extending the length of the clip in which it resides by slip editing the right hand end of the clip out by a few ticks

Last kick is on the downbeat of the last full measure or is actually the very last event in the project? Is the kick on its own audio output, or are you mixing in Battery and just using one stereo out? Any parallel compression? Did you record/sequence the pattern yourself? If not, check for controller in the Event List of all tracks driving Battery. And try watching the kick-related parts of the Battery UI during playback, and see if something moves/changes. And, of course, make sure the velocity isn't just below some threshold where a quieter sample is triggered.
 
If all else fails, maybe try substituting a different drum synth, and see if the problem persists.