Running xterm over SSH with a DISPLAY parameter correctly set can show an error for the Drawable.

# xterm
X Error of failed request: BadDrawable (invalid Pixmap or Window parameter)
 Major opcode of failed request: 55 (X_CreateGC)
 Resource id in failed request: 0x5a
 Serial number of failed request: 3
 Current serial number in output stream: 4

To solve it add or uncoment in ssh_config

ForwardX11 yes
ForwardX11Trusted yes

And restart the SSHD service.