I had a similar problem. I replaced batteries, did blue-tooth on/off, remove/install software, bluetooth on/off etc. I tried from two devices running android 5, one intel and one media-tek hardware and the mooshimeter would program ok and then remain in the hardware bootloader with 1 second led flashes. I was ready to give up after a several days of this and then found a phone with android 8 and everything programmed ok, my mooshimeter is working again.