Tennis rules ban cannabis but allow CBD

The International Tennis Federation’s 2020 list of banned drugs prohibits the use of both natural and synthetic forms of cannabis. However, cannabidiol (CBD) has not been banned. Players have been warned that some preparations of CBD contain traces of tetrahydrocannabinol (a psychoactive constituent of cannabis), which could result in a positive test for a banned substance. 

Source: https://www.thegrowthop.com/cannabis-news/how-pro-tennis-players-feel-about-cannabis