X11 forwarding not working (using Putty to connect to a CentOS 8 VM). What can be wrong?

I simply can not make graphic softwares run on my CentOS 8 VM. I installed it with no GUI support.

I have Xming running.

I am using Putty (my local machine is Windows 10), has checked the X11 Forwarding box, has already edited sshd_config file following http://www.straightrunning.com/XmingNotes/trouble.php instructions and when trying to run sudo gparted I keep getting

Unable to init server: Could not connect: Connection refused

(gpartedbin:1559): Gtk-WARNING **: 19:22:28.507: cannot open display:
--runtime cannot be used with unmask

Any hints?