Check ssh server config:
# sshd -T | grep x11 x11displayoffset 10 x11maxdisplays 1000 x11forwarding yes x11uselocalhost yes
Adapt /etc/ssh/sshd_config if different from above.
If it still doesn't work, disable IPv6 by setting AddressFamiliy to "inet":
##BAD: # sshd -T | grep address addressfamily any listenaddress [::]:22 listenaddress 0.0.0.0:22 ##Good: # sshd -T | grep address addressfamily inet listenaddress 0.0.0.0:22
Restart sshd:
systemctl restart sshd.service
If using the default Gnome Vino server, disable encryption which is incompatible with (some?) other clients:
gsettings set org.gnome.Vino require-encryption false