There is also an issue with conceptual leakage, most noticeably I've found with devs well versed in one language bending another language into behaving like the former.
You also see it when people who've mostly done imperative programming tries their hands with a lisp or some ml based language. I've been there myself. You still find yourself using the equivalent of variable bindings, trying to write in an imperative rather than declarative style.
I guess when trying to learn a new language in a different paradigm you also need to unlearn a lot of the concepts from the former language.
I write elixir that smells like rails, but as the months move on, I change.