Warner Bros. planned Flash solo film (which may or may not be a version of Flashpoint) has been delayed until 2021, according to Variety.
The Hollywood trade reports filming was expected to begin in March, 2019 for a projected 2020 theatrical release. However, that schedule has reportedly been delayed due to issues with the script - a delay that Variety says is extended due to Ezra Miller's role in the third Fantastic Beasts film, which begins filming next summer.
This means filming on Flash will likely not commence until late 2019, in which case the film's will be pushed back to 2021.
Flash will be directed by John Francis Daley and Jonathan Goldstein, the writers of Spider-Man: Homecoming.