Why does my drivtrain skip under hard torque?
Skipping like that is usually worn cassette, chain or chainring(or all 3).  Considering it's only doing it in the highest gears, my first guess would have been the cassette.  But since it's only a month old, it's much more likely to be the derailleur is mis-aligned just a little bit.  You say the derailleur is "ever so slightly bent", that little bit can make a big difference if it's out of alignment with the gears.  Also, as Criggie says in the comments, the cables "settle in" a little after about a month or 2 of riding, that's very common, and the reason most shops offer a free tuneup in the first year you own a new bike.  May be worth checking to see if the shop you got it from offers one.