ASA 5506 EasyVPN & DMZ "ERROR: This configuration cannot be modified with Cisco Easy VPN Remote enabled."

I need to set up a DMZ interface for my ASA 5506 (IOS ver 9.5.2) that's set up as an Easy VPN client. When I try to modify the third interface I get this: "ERROR: This configuration cannot be modified with Cisco Easy VPN Remote enabled."

Googling around I found this thread which says such a thing should be possible but doesn't mention the above error message: https://supportforums.cisco.com/discussion/12460931/dmz-interface-asa-5506-x

Googling around for that error message I can only find the below two posts that don't seem to have anything to do with my issue:

https://supportforums.cisco.com/discussion/11219271/ssl-vpn-not-working
https://supportforums.cisco.com/discussion/11092461/asa5505-vlan1-subnet-change-remotely

I have the sneaking suspicion I can't have Easy VPN (client) and DMZ set up on the same device but I hope I'm wrong. Any help is appreciated.