On 58.png and 61.png you can see that on the top and bottom of the darkened the texture, although repeated as you state, is not quite aligned correctly. I have attached 59.png and 60.png to show that the background texture repeats properly on all of the other menus.
thx. turned out i had to update the blockdata files
Since submitting this bug report, I have found issue MC-123363, which appears to address the issue. Since I can't find a way to close my report, maybe a moderator could close it and perhaps tag anything that is not included in the other report on it.