Temporary Solution: On high resolution monitors more than 2048 pixels wide, the iTunes window needs to be shrunk to a smaller size. Do not run maximized. Shrink the iTunes window until the Store renders properly.
This appears to be a rendering issue with higher resolution monitors.
My current resolution is 2560x1440, Windows 10 Pro, iTunes 12.3.2.35. iTunes Store and the New Tab will properly display until an iTunes resolution of about 2048 pixels wide. Anything wider than that, the windows starts going crazy.
I think it has to do with the "Highlight" album and artist selections at the top of the browser. I think it can't draw correctly past 2048 pixels. And since that's a base 2 number (2^11), it's probably a programming error within the iTunes browser.
I spoke to a "Michele" through Apple Support and she documented everything I found and marked it as a bug.