Hello, I'm here to help.
This is usually not a problem, your motherboard may be using it as a RAID 0 array of single hard disks, which is no different than using a single hard disk directly.
You can go to the BIOS and find the disk mode and adjust it to AHCI to get it to work as a separate drive. You can enter the BIOS menu by pressing DEL or F12 at boot time (possibly other keys depending on the computer, see the device manual for details). But since it works fine now, I wouldn't recommend you adjust it, it might cause additional problems.
Please feel free to reply. This is not a live chat channel and I may be in a different time zone than you(UTC +8). As a result, replies may be delayed and I may respond minutes to hours later.