Yeah, they're finicky. Little tip - always make sure the barcode is flat when you scan, helps sometimes. And be gentle with placing items in the bagging area. These machines have the sensitivity of a high-end scale... which is annoying at the grocery but hey, it's tech, right?
That internet speed and storage issue are completely unacceptable, and 1GB when they promised 100TB? I think everyone in this sub can learn from this. It's buyer beware on Kickstarter. Do you think you could try flashing a different ROM on it to at least make the phone usable?