(like you suspected) somebody is already running one (or more) asic's on testnet4.... why... i really wonder why.... why would you run an asic on a network that's designed to test ... why won't you let others get some tBTC to play with... At least, if you're nuking the testnet, create a faucet where others can have some tBTC to test out their setups...
That's what I expected. I'll just give up already, there's no point to try mining against ASICs.