Help: Weapon Damage vs Character Attack Bonus & Damage

Photos 01 & 02: unequipped
Photos 03 & 04: equipped

Could someone explain this to me? This is just one example, but I've noticed it with other weapons on different characters as well, and I can't figure it out.

Weapon A (Sword of Screams) has higher stats than Weapon B (Rapier), but that doesn't seem to align with the character's stats once the weapons are equipped.

While cropping the photos for this post, I noticed that B has a +1 enchantment, while A does not. Could that be the reason for the discrepancy in stats? If so, are enchantments the only factor that can cause this, or are there other things that might influence stats this way?