Smells fishy... They are using a custom firmware. Is it possible that there is a backdoor for calling home in case of a found block?
Got mine a month ago from china.
https://tinychiphub.com/products/bitaxe-gamma-1-2-th-s-bitcoin-miner
Discussion
As they say on their website "It is totally ok to install you own firmware but we recommands to install TinyChipHub fine tune version for a better cooling and performance."
I have flashed the official v2.3.0 by skot and everything works great.
PD: I have nothing to do with Tinychiphub, they have given me a good service and that is why I recommend them.