Ah, it's an external connected by USB. In that case my example of mismatch between SATA speeds is less likely - if you bought a complete external drive, no doubt the components were matched. But maybe the USB enclosure or the connection is not right.
I suggest two troubleshooting tests you could try. First, try connecting the unit to one or more other computers to see if the problem happens there. If it does, you have a problem with the external unit; if not, there's a problem with your laptop's ability to deal with the device on the USB port.
If the problem is in the external system, you could try opening the external drive and removing the hard disk from it, then mounting that drive as an internal HDD in another computer. If it works that way, you have to suspect the flaw is in the external case. But if the drive malfunctions when in another computer as an internal, you know the drive itself if flawed. In that case, get as much data backed up from it as you can as soon as possible. Then go looking for a replacement.
It's also possible that the problem is a loose connection within the external drive unit, and you might find it and fix it simply by taking the disk out of the case and then replacing it. May not be likely, but possible, anyway.