So if I try to eject the drive from the notification area in Windows 10, I get the message that the drive is being used by another device.
So I downloaded and installed “USB Safely Remove” and it tells me that this process using the drive is “cmdagent.exe”
I have HIPS, Viruscope, web filitering and auto containment disabled. I just use the firewall.
It goes even deeper than cmdagent.exe. Windows also is known to block it. I once did an online search on this and found various topics about it. It turns out Windows also has a way of interfering with safely removing external drives. Linux is said to always facilitate safe removal.