Hi, I am Dave, I will help you with this.
KB5039302 is an optional preview update of the full release version of the July update, that was released on the 25th of June and many people cannot install that update, it is also reported to contain bugs, Microsoft was meant to pull that update.
There is no need to install optional preview updates, it is best to just install the normal monthly updates, below the updates list is a switch for 'Receive the latest updates as soon as they are released', turn off that switch to stop getting preview updates.