A common reason why this is happening, is that you have a real copy of the two GSX packages in the Community folder instead of a Simlink, which is what GSX installs by default.
It’s possible to end up with a real copy without realizing it, if you made a backup of the Community folder and then restored it, perhaps when you enter the beta. This because the restore method you used might not be aware of Symlinks, it’s usually an option in backup software but, for example, if you just copy and paste the folder using Windows Explorer, it will convert Symlinks into real folders when pasting, so you can be easily end up with the Symlinks converted to real folders without realizing it.
The problem of having a real folder instead of a Symlink is that the sim will “see” a GSX package, but the FSDT Installer/Updater will only update its own copy the Simlink was supposed to point to, so if an update to the package was required, you’ll miss it in the sim, since the two folders are not linked anymore and they are individual folders (that’s without even mentioning you are wasting twice the disk space).
So, check the GSX packages in the Community folder: if they are real folders (they are missing the small arrows on their folder icon), REMOVE BOTH OF THEM. Then, start the FSDT Installer, and select Relink, so the proper Symlinks will be recreated.