Help with CZH-05B

[Sctiger]

So...as someone once said, most victories are short lived. Since I was so focused on getting my outdoor speakers to work, I haven't checked my new FM transmitter in a while. Before I unplugged the transmitter, it worked fine. Tonight I decide to make sure everything works together. After I powered on the unit, it sporadically blinks and the mute symbol is on the display. I went through the "setup" protocol in the instructions where you use the power button as "enter". After it switches from "108.00" and "76.00", the unit won't switch off by holding the power button. Any thoughts?