I've heard a little about the break-in period for new ukes. I just purchased a new Kala Acacia Tenor and have greatly enjoyed owning it thus far. However, in the last day or so I've noticed it delivering less sustain than usual. I just received it last week and it had excellent sustain right out of the box. The strings are new Aquila high-G tenors. I'm 85% sure it isn't all in my head. Could this be due to a break-in period that I should patiently wait out or should I be concerned?