The pattern itself appears to be your problem. The dithered gray parts seem to be giving your PJ fits. Note that they are distorted, but the black box with white text repeats in good vertical alignment down the screen and is legible. If this was a problem with your display, every part of the pattern would be pulled out of alignment and distorted.
Find another pattern, and don't tile it.
Find another pattern, and don't tile it.
