i6s Plus polarizer issues- dark screen on landscape mode

I replaced a 6s plus screen and my customer has custom polarizer glasses of some kind and when you look at the display wearing the glasses in portrait mode you can see it, but when you turn the phone sideways the whole screen gets 90% dark rendering it unseeable. I tested this with two screens and both same result. Is this a screen defect in the polarizer? I tested it on my 8 with screen replaced and through the glasses you could see fine both directions. Please help. My screens aren’t aftermarket either, they are mid grade from a company in GA. I’ve done resets, soft reset, replaced battery and nothing. Without the glasses the phone is 100% perfect and you can see it perfectly. Thanks.