Upper bonded retainers problems. Will my middle lower teeth get damaged hitting the upper retainer?

Hello I just got upper & lower bonded retainers, when I close my jaw the 2 front lower teeth hits the upper retainer (sits right on the metal). Upper & lower molars can't touch each other when I bite down because of it. The upper retainer is glued to the most upper part of the teeth right below the gum line. My dentist said that is the best place for it and won't lower it. Is this normal? I am worried that my 2 lower front teeth will get damaged in the long run constantly hitting metal.