Underc0vernerd

I am new to spas as we just moved into a house that has one. Based on the tag on the side it looks like a hydropool HS5000G. Not sure what year or how to tell what year. It’s older though. My question: Is it normal for the jets on one side (the lounge side) to slow down or even turn off completely if you turn the jets up on the other side (seat side). It seems that the only way for all the jets to be working at once means none are really working that well. If you want a nice strong jet on one side it turns off (or almost turns off) the jets on the other. It turned all the way up it stops the jets on the opposite side completely. Is this just how they work or is there something wrong?