Tether boot on one computer fine but not on another???

I have a tethered apple tv 2. The guy I bought it off can tether boot it no problem. I however, when brought it home followed his instructions and I can’t do it cause 1. the option to tether boot is greyed out and 2. after I finally got it and pressed the tether boot it says it’s a untethered apple tv and I don’t need to do that process. So because this is an older version jailbreak I took the advice of one of the guys here and copied his older version of Seasonpass cause we know it works for sure. Nope when I try it it still says it is untethered and I don’t need to do that. I am completely confused. Why does it work on his computer and not on mine? Is there something wrong with my computer? Any help would be appreciated.