I have Windows Media Encryption disabled for my user. 
The client shows that it is set to false for my user.

That should decrypt any DDPE encrypted removable media that I plug in.

It doesn't. 

All it does is do a scan to look for more items to encrypt.

I've reinstalled the client on the host, no change.
I've made sure there's no excess allow-listing that might include my media, no change.