Please make report in https://downloadcenter.intel.com/download/18455/Intel-Solid-State-Drive-Toolbox Download Intel® Solid-State Drive Toolbox , save it to file and attach to post, we need to see full SMART log.
Checking the SMART Details from the SSD, it is working correctly. The difference in the reported size does not seem to be an issue in the SSD.
As I mentioned before, Intel® SSD's have a overprovisioned space to be used for additional features and enhanced performance, this space is not available to the user. This space can be modified with 3rd party tools to increase overprovisioning or to match a specific drive size. In this case, it seems this was modified in your drive in the past, causing the usable drive size to be 144 GB.
In this case we advise you to contact the Place of Purchase, or the previous owner of the drive since these types of changes are not supported by Intel.
We cross-checked the information from your SSD and it is an Intel® Solid-State Drive 520 Series 180 GB according to our records.
We would like to mention that the capacity available to the user may be modified with 3rd Party Tools. In some cases a user would do this to meet specific system requirements, like increasing overprovisioning, or to match a determined capacity for business needs. Intel does not recommend tampering with the original condition of the drive, so we don't support this type of changes.
Checking the portion of the SMART attributes from the screenshot you provided, the SSD does not show any sign of hardware problems.
If you obtained the drive in this condition and it was advertised as a 180 GB drive, we would advise you to contact the place of purchase and check with them about this matter.
Did you clone from another disk to it by any means? Can you paste a screenshot of your disk management utility?
Also I noticed that you're connecting to it with a USB adapter. Have you tried connecting it to SATA directly or to USB with an adapter of another model?
Honestly I am not sure what you are actually experiencing. Ths over-provisioning theory from jonathan_intel is just plain guess to me. Thing is are you the first owner of this drive? What can you tell about the history of this drive (like when did you buy it, since when this problem appear, what have you done before it appear, etc.)? Have you actually set up / adjusted something explicit, like Host Protection Area?
I've already told you what I can think of to troubleshoot, by the little information you've provided.