Low DK Beholder level 3 mastery bug

Description of the bug: (optional screenshot/video): Level 3 Beholder doesn't seem to give additional 10% mastery, looks like to be still 5% instead.
What is supposed to happen?: As screenshot suggests, beholder level 3 should give 10% additional mastery as tool tip suggests
Where did you find and/or notice this bug?: When I added my mastery to level 3 instead prioritising maxing out berzerk (leaving berserk at lvl 29 in favor of 5% additional mastery), I noticed my min range of the damage didn't increase.
A step-by-step guide to re-producing this bug (optional):
Extra information (optional): Total EQ WA 19, weapon(spear) WA 114, ran my calculation against the damage formula, it tallies with mastery of 65% instead of 70%.

 

Just an update, seems that 10% mastery is granted at beholder level 4 instead, so it looks like just a typo in the tooltip