Middle mouse button duplicates oak instead of proper one

I built a little hut out of acacia wood and put an iron door down to get in. I placed an acacia button down, then later once I decided I wanted it on the other side of the door I used the middle mouse button to replicate the item and I got an oak button instead of an acacia button. I (just) tested it and it does the same with all wooden buttons, they all give oak buttons. Stone buttons still give a stone button. This does not replicate with doors. trapdoors, or slabs.

(Version is most likely incorrect, I'm not sure where to find it. Main screen bottom right says v1.4.2)