Ferocious Roar’s Scaling Broken at Level 20

Ferocious Roar’s increased damage for socketed warcry is broken specifically at level 20 (doesn’t matter if it’s corrupted or not, just that it’s level 20). The scaling for this damage begins at 30% at level 1 and goes up a flat +3% every level through level 19 (at which point it is +84%). But for level 20, this damage increase actually DECREASES to +58%. Then, for a level 21 ferocious roar, the +damage % is +87%, the expected value for level 20. After level 21, the stat continues to increase at a flat +3% as expected.