Does this specifically happen with the default version of the plugin as well, or only with the modified version you're using?
Looks like the default one has the same problem. I think it's only a problem with action sequence skills.
Secondly, are your shield equips actually shields?
Yes. They are regular shields.
This is the skill that is attacking twice when using a shield:
I think I fixed the barehanded several attack problem, but I made the same mistake for the weapon version and never had an issue. I had the "dual wield action" include another "dual wield action." This is the attack skill that is leading to several attacks when barehanded: