[MC5C]

You don't say what kind of guitar it is, or the maker. For me, a guitar moves a bit when it's brand new, can take up to a year to really settle down. This is the season when it moves a lot, as we go from humid summer to dry winter. Adjusting the truss rod to correct a fret buzz is not the best way to go about it, you adjust the truss rod to set relief, and that's the only thing you do with it. While it's true that incorrect relief might cause a fret buzz, that's a side effect, not a primary effect. Anyway, if it's a generic factory made instrument of little or no intrinic value to you yet, send it back. If it's unique in some way, or means something to you, fix it. Personally I don't get buying an instrument mail-order than I haven't played, but I'm about to advise a friend to do exactly that, for the same reason that you probably did - not available near me, so if I want one I need to do the mail-order thing. Advice to get or do a basic setup is correct, advice to use a fret rocker to find the high fret is correct, if you decide to keep it. It might be something else causing a buzz, not a fret, keep that in mind.