MobaXterm cannot authenticate

[root@SRV01 account]# echo $DISPLAY
localhost:10.0
[root@SRV01 account]# xeyes
MobaXterm X11 proxy: Unsupported authorisation protocol
Error: Can't open display: localhost:10.0
[root@SRV01 account]# xauth list
srv01/unix:10 MIT-MAGIC-COOKIE-1 6ef5de64350894239bbfa7eb7f69cdc2
localhost/unix:10 MIT-MAGIC-COOKIE-1 02adc03f69c6431ea06e309a309ddb31

What else could be wrong? RHEL 7.4, religiously patched to latest release.
Running MobaXterm personal edition v. 8.4 on Windows 7 Enterprise