Charm Effects Not Applying to Fishing Pole Damage

The Charm of Fatigue, Charm of Venom and Charm of the Subterranean - increases melee damage in the character stats UI when holding a fishing pole, but their effects are not applied in the actual damage formula. Despite the increased melee damage shown in the stats, my fishing damage remains the same as without the charms equipped.

On a screen damage is 1167, so excepted damage ~1167 for regular attacks and 1750 for crits. Results are 933 and 1400 for crits, which are exactly my stats w/o Venom buff.

I haven't conducted tests with other weapon types to verify if this issue is specific to fishing poles or applies more generally. A review of how charm effects are calculated in the damage formula for fishing poles would be greatly appreciated.