two flights changed by kulula in last week at short notice

Twice in the last week has a flight that I booked for my daughter been changes with less than 24 hour notice. Seems either their planes have technical issues often, or they cancel flights if there isn't enough utilisation. One flight was changed to an earlier flight and the other flight was changed to a later flight. This is after my daughter has already checked in. This unreliability will make me switch to another airline.