ssh: why my disabled forward X11 for specific host don't work?

I use an alias for ssh alias ssh alias ssh='ssh -t -K -Y I want to use ssh forwarding X11 except for one host so i did this: vim .ssh/config host myhost port 22 ForwardX11 no HostkeyAlgorithms +ssh-rsa PubkeyAcceptedAlgorithms +ssh-rsa but.. ssh myhost sh: xauth: command not found myuser@myhost$ seems my option is ignored..why? I also tried ForwardX11 no ForwardX11trusted no but no success. A workaround can be this... \ssh myhost so -t -K -y is ignored, but I prefer a more clean solution I forgot: the remote server use dropbear reading this page i see is possible to disable X11 for a specific key on server vim .ssh/authorized_keys no-X11-forwarding ssh-rsa...... but in this case it refuse also \ssh command! ssh myhost X11 forwarding request failed on channel 0 Connection to myhost closed by remote host. Connection to myhost closed. \ssh myhost Connection to myhost closed by remote host. Connection to myhost closed. Using this line on server works..but no for pubkey, it require the password no-agent -forwarding, no-port-forwarding, no-x11-forwarding ssh-rsa....