WD Green 240gb SSD really slow to boot


I’ve just installed a WD Green 240gb SSD into an Emachines E250 netbook. This has an N270 Intel Atom Processor, and it’s running W10 Pro. I’ve installed a different brand SSD into a similar netbook with excellent results.
The problem here is that when I boot up, the Windows logo appears, then the little rotating dots start to appear - one by one. In the old HDD boot they would all appear, do their rotating thing for about 20 or 30 seconds, then the sign on screen would appear, but with SSD installed, the dots slowly appear, and slowly rotate for four to five minutes before the sign on screen appears.
I first used Macrium Reflect to clone my original HDD and when this problem appeared I repeated the cloning process but it made no difference.
I then used the microsoft Media Creation Tool to make a bootable USB and instead of cloning the HDD, I did a clean install of Windows only, no other programs, no data, and its still takes 4 to 5 minutes before the sign on screen appears.
It seems to me that the problem lies within the SSD itself, but where, and how do I overcome it?