You new drive is being detected and seems to be operating correctly, the limited capacity is due to the RAID basic specifications.
In standard RAID configurations all the drives must have the same size, if you create an array with drives of different sizes, the capacity will be limited by the drive with the lower amount of space. In this case, since you are creating a RAID 0 with with a 32 GB SSD and a 240 GB SSD, the array is created using 32 GB per drive (this is around 30 GB per drive as detected by Windows). This results in a RAID 0 of 60 GB. The remaining storage space in your new Intel® SSD 730 will not be used in this configuration.
For RAID arrays, a best practice is to create arrays with drives of the same type, size and speed; this way you can take full advantage of your drives.
Also, take into consideration that RAID 0 does not provide data redundancy, if one of the members of a RAID 0 fails, you will lose all the data in the array.
If you want to take advantage of all the space of your new Intel® SSD 730 240 GB, it would be better to use the drive as a standalone drive, or create an array with a drive of the same type.