14 magic pen runes majour bug; the n-th billionth time i have reported this now and still not fixed

Before 14 magic pen would visually show 13 magic penetration in champion select, but still give 14 magic pen; a bug, but didn't affect gameplay.

NOW a few patches ago, which I reported this multiple times, even when it was just a visual bug, but is now a gameplay bug too. 14 magic penetration would actually only give 13 magic penetration in game EVEN TO THE POINT it turns ALL 15 magic penetration items into 13 magic penetration.

Marks (reds) and Glyphs (blues) give 14 magic penetration, or they are suppose to be...