Carpet tiles require 2 reed fibers to build, but deconstructing a carpet tile gives back only 1 reed fiber. (The resulting reed fiber had some weird effects in terms of building mass, too: it says it's 1000g of reed fiber, when I built another carpet tile that used that fiber, it was 203kg instead of 202kg.)
Steps to Reproduce
deconstruct any carpet tile
This issue has been fixed in either a future version or updated in a previous version.