Both my drives are shown as Fixed hard disk in System Information from Administrative tools.
I am using a Acer Veriton workstation that originally came with windows 7, later windows 10 was installed and updated to 1809.
When I select the "Safely Remove Hardware and Eject Media" icon in the system tray, Windows 10 displays the options to Eject both my fixed spindle and solid state drives.
Although windows knows my drives are FIXED, components of the O/S are not finding (or bothering to look for?) that info and assuming that they are removable.