Certain CFDs may not be available for short selling due to restrictions imposed by local financial authorities aimed at safeguarding the integrity and quality of the securities market. As a result, these regulations may impact the ability to short sell specific CFDs.
You can always check whether a CFD is available for short selling by reviewing the Trading Conditions under the Instrument section.
Note that the state of the instrument is not static and can change due to risk, availability of shares in the market, etc.