If Options > Advanced > Midi "Cut Long Notes at Part End" is not checked, any note on events before the end of a clip will fully play.
If that option is off and you hear notes that you don't see near the end of the clip, open the midi clip by double clicking and zoom way, way in to see if there are any Note On event slivers right at the end of the clip. If there are, the full note lengths will still play unless you turn that option on.