According to The Hollywood Reporter, there are two scripted series in the works at HBO Max on the world Robert Downey helped create back in 2009. Downey is on board to executive produce both shows along with Lionel Wigram, who also produced both of the films.
Vanessa Armstrong, https://www.tor.com/2022/04/05/hbo-max-and-robert-downey-jr-are-building-a-sherlock-holmes-universe/
We don’t know much about these scripted series yet—we don’t even know, for example, if Downey will reprise his role of Sherlock in either of them. And we also don’t know if the two shows are inter-connected in any way besides taking place in the same world as the two Holmes movies.