It recognized it originally as a 1 tb, and now it is recognizing 500 gb
The cloning software probably cloned the partition itself thus it's being 500GB. Ok, so open Windows Explorer (file explorer if you will) and right click my computer. Next select manage. Enter disk management (local) locate your drive (1tb SSD) and check if you have 500 gig of unallocated space. Now if you do, you can try to expand the volume onto the unallocated space but I'm not sure if it will work since it is a boot drive (I think it will though). If it don't work and no third party utility can help you either you have two options the way I see it.
Run the drive with 2 500 gig volumes.
Backup everything you want to keep and install Windows from scratch (remove the partition and format a new one in the progress).
IF however disk management shows the drive as 500 gig and it IS a 1tb drive, then the drive have a problem and probably need to be replaced.