Not sure what you mean by that, as every resistive load will do exactly that.It's not often you'll find a load that pulls higher current at higher voltage.
Something may be wrong with your TEC or your measurements. A 12710 should draw ~10A at 12V, and those are its max ratings.At 12 volts the TEC is only pulling about 6 amps.
Not sure what you mean by that, as every resistive load will do exactly that.