Bamboo duplication glitch with pistons

I noticed a player using this glitch on our SkyBlock server for which I currently act on as developer (we run Paper 1.14.3). I was able to go and recreate this on singleplayer with version 1.14.3. I have not tested this issue on any other versions.

 

The recreation can be made by building what is in the uploaded images (I am not a redstone engineer, so I don't really know how to explain the details).