Bug when Masterworking Blood Moon Breeches at level 4

Today I had a drop of Blood Moon Breeches.
They had a +1 roll to “Hellbent Commander.”
After completing masterwork at level 4, it was shown a +1 roll to “Hellbent Commander.”
So, the skill should now be at +2.
However, the item still shows +1, and the skill tree only shows +1.