Playtest - Private Version

I am having a problem, when I try to select another private version to update the play test that I have active, it does not allow me to select another private version. Does anyone know why this may be happening? I greatly appreciate any help or guidance on this topic. Thank you.

Currently, the play test is with the private version dated 04/02/2024 but the one you want to use is the private version dated 07/25/2024.