Harley Benton SC-Custom III P90 Black

I've always wanted a guitar equipped in P-90 pickups. I found this particular HB model with lots of positive reviews here and on YT with very impressive sound samples. Quite narurally I ordered the SC P90 and, voila!... here it is! Thomann - as usual thanks for fast and reliable delivery. The guitar arrived in perfect shape, absolutely flawless, the only thing I had to do was lower the string action on the bridge to my liking.
The only thing that bothers me a bit, sound-wise, is the sound I get in the middle position, i.e. with both pickups engaged. At full volume of either the sound is hollow, resembling that when you turn on two pickups out of phase. I wonder if it's possible that my specimen was improperly wired in manufacturing, or it's typical for all guitars of this model.
Nonetheless, I enjoy playing my newest HB very much, as the sound in any pickup configuration is vastly different from all my other guitars.