Ah, I see. So editor versions older than v4 store their settings differently. The launcher will pick up the version you set in the older version, but it won't see when you have checked "beta updates" in the older editor version. Eventually few people will be running the older editor versions, so this won't be an issue.
Anyway, it's best to set the version using the launcher. When you start Spine, the launcher shows a splash screen and a Start button. If you have checked Start automatically the launcher won't stop at the splash screen. In that case click anywhere on the launcher when it first appears, that will cancel the auto start. On the splash screen you can choose the language and version. Choose Latest beta for version, click Start, and you're good to go.
