yeah i have been scratching my head over this for two days now. yes the are on the same default gateway. both laptops are wireless and the antminer is wired. the only thing i havent tried is factory resetting the antminer. i kinda dont want to do that because its currently mining and if i reset it and then i cant get to the backend then i wont be able to set it up.
I'd plug my laptop in to the same switch the miner is plugged in to, grab a wired IP and go from there. I know you've talked about IPs, but did you by chance have it bookmarked by name? I'd kill the bookmark and for good measure do an ipconfig /flushdns from an admin command prompt.