Board Thread:Versus Debates/@comment-3523655-20200804020538/@comment-39350828-20200820223831

It's probably just a plot hole. Even if he is only limited to non-hiden non-kekkei genkai techniques there's still a lot of stuff he had no reason not to copy. Anyway unless @Flatzone says in which chapter kakashi said he can't copy hiden, him not being able to do it just sounds like your headcanon.