I just solved this issue by factory reset
I followed this topic and tried all the possibilities and finally solved this issue. I hope it works for you guys.
Reset:
1. Turn off AMPLIFi 150
2. While holding the "Tone" & Pressing Down "Volume" turn on AMPLIFi 150
Then my AMPLIFi 150 works and it seems no issue with the firmware which has been refreshed.
Vincent