When using Tinker Items this happen:

• Offhand Weapon do an animation, but the damage comes from the main hand
  -- Also the Main Hand weapon get the durability damage (only when it is a tinkers item; else the item get no damage [Example: have a regular minecraft:iron_sword in the mainhand])
• While "Attacks require full energy" = true
  -- It ignores it and I can attack any time
• Try also to add the Items into the "Item Whitelist"
  -- no changes
  -- try also adding ":*" at the end for all Meta or direct ":11" also don't work

My Config:
https://pastebin.com/X2rKGYiJ

I did not find other Tickets to Tinkers Issues, so I think the bug lays in my modpack.
Will test it again in a new instance and post the results soon.

Created a total fresh Instance 1.12.2 - newes Recomanded Forge Version, same issues.

• Try to delete the config - didn't work

Notes:

• Using one Tinkers Item at the same time works fine
  -- But having two items in the hand (off and main) it bugs
  -- [The Main Hand weapon get the durability damage (only when it is a tinkers item; else the OFFHAND Tinkers item get no damage [Example: have a regular minecraft:iron_sword in the mainhand])]

So in this case, I think there is truly a bug and its not a bug on my modpack.

Thanks for reading so far and hopping for a solution.

I'm experiencing similar issues. Luckily it's not game-breaking, but it does make the mod feel a bit redundant since dual-wielding is half the reason I have this mod in my pack.