I noticed something once I hit level 20. I use two weapons, stats as
follows:

Pugius: 5/21 piercing - main hand
Dwarven Axe: 6/26 slashing - off hand

Now before level 20, the damage from these guys was pretty standard,
usually 10-11 for Pugius and 12-13 for the axe.

Once I hit level 20, the damage from the dagger seemed to stay the same
(I haven't seen anything higher than 11), but the axe now does up to 18
damage.

I know at level 20 you start doing more than 2*damage+1, but I was
wondering why it only seems to be affecting my axe's damage.

Any ideas?

Jyzan