Scaling Mana Regen Runes Values Off
Looking through my runes I noticed that the Greater Seals of Scaling Mana Regen and the Greater Glyphs of Scaling Mana Regen both show +1.2 Mana Regen / 5 at level 18, yet the Glyph shows as +0.06 / 5 per level (at 18 that comes to 1.08 / 5) with the Seal showing +0.065 / 5 per level (at 18 that comes to 1.17 / 5). It may just be an issue with the tooltip when you hover over the runes, but even then it would be annoying to find that you're not actually regenrating as much mana as you should from your runes.
Link to photos below: