Yeah... Don't buy plugs off Amazon... If they look like a great deal, be suspicious..!
I'd be looking at what the actual difference is between those two plugs.
It may be that you just bought dodgy fake plugs, but it may be that the other plug is higher rated, which leads you to the question: WHY did someone put uprated plugs in the bike?
Better spark?
To solve a problem?
What I'm saying is: Just because the issue appears to be 'fixed', don't stop looking for the problem!