The dual wield was broken day one. Some of us have reported it immediatly (personnaly I have reported it at every new patch).
Someday during the different version of the patch 3 (hotfix), they've changed it but only to broke it differently (attack bonus was missing - and i've reported it). Funny thing is they never said they changed it on the log of the hotfix.
With this two-weapon's fighter are not viable. It made me stop playing.
Also, but I'm not sure that Larian will respect the 5e here, you are not suppose to be able to use your bonus action to strike if you haven't strike with your main action first.
Dual wielding is very viable, just not 5E compliant. For example, look at the Githyanki rogues at the bridge. Main hand attack, off hand attack, off hand attack, and haste attack. You just need a potion of speed and a Thief Rogue build with two short swords. It’s deadly.
