For some unexplainable reason, despite me clearly picking the dueling fighting style when making/editing my character sheet, the fighting style under Bonus Actions & Actions in Combat always says I have the two weapon fighting style. No matter what edits I make, it is always set to this.

Is this a bug or am I missing something in character sheet rules?

All characters have two weapon fighting, which is separate from the two weapon fighting fighting style. the fighting style lets you add your strength or dexterity modifier to offhand damage, whereas the innate ability just means you can use your bonus action to do an attack if wielding two light weapons..

Thank you for clarifying!

I wasn't aware that two weapon fighting the action was a separate thing.