SSH Keys Issue

[Oosmus]

Hey there, I'm running into an issue that isn't unknown, but looks like no one has ever posted a solution for this.

guacd[165]: INFO:	Creating new client for protocol "ssh"
guacd[165]: INFO:	Connection ID is "$d11a8e0c-7f21-44a7-b538-d52f643bdbd3"
guacd[331207]: INFO:	User "@def06cd2-7974-405a-aa29-b9571ee6d086" joined connection "$d11a8e0c-7f21-44a7-b538-d52f643bdbd3" (1 users now present)
16:02:41.640 [http-nio-8080-exec-2] INFO  o.a.g.tunnel.TunnelRequestService - User "Oosmus" connected to connection "14".
guacd[331207]: INFO:	Auth key successfully imported.
guacd[331207]: ERROR:	Host key not found for <hostname>.
guacd[331207]: ERROR:	Host key did not match any provided known host keys. 
guacd[331207]: INFO:	User "@def06cd2-7974-405a-aa29-b9571ee6d086" disconnected (0 users remain)
guacd[331207]: INFO:	Last user of connection "$d11a8e0c-7f21-44a7-b538-d52f643bdbd3" disconnected
16:02:48.307 [http-nio-8080-exec-3] INFO  o.a.g.tunnel.TunnelRequestService - User "Oosmus" disconnected from connection "14". Duration: 6666 milliseconds
Exception in thread "Thread-51" java.lang.IllegalStateException: Message will not be sent because the WebSocket session has been closed
	at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.writeMessagePart(WsRemoteEndpointImplBase.java:449)
	at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.sendMessageBlock(WsRemoteEndpointImplBase.java:307)
	at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.sendMessageBlock(WsRemoteEndpointImplBase.java:249)
	at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.sendString(WsRemoteEndpointImplBase.java:191)
	at org.apache.tomcat.websocket.WsRemoteEndpointBasic.sendText(WsRemoteEndpointBasic.java:36)
	at org.apache.guacamole.websocket.GuacamoleWebSocketTunnelEndpoint.sendInstruction(GuacamoleWebSocketTunnelEndpoint.java:152)
	at org.apache.guacamole.websocket.GuacamoleWebSocketTunnelEndpoint.access$200(GuacamoleWebSocketTunnelEndpoint.java:53)
	at org.apache.guacamole.websocket.GuacamoleWebSocketTunnelEndpoint$2.run(GuacamoleWebSocketTunnelEndpoint.java:253)
guacd[165]: INFO:	Connection "$d11a8e0c-7f21-44a7-b538-d52f643bdbd3" removed.

Things I have tried:

• generating new ssh keys that I confirmed worked on another machine without using Guac
• removing the username from the username field
• keeping or removing passphrases
• using the older PEM method, or the newer openSSH method.

The most progress I can make here is connecting and getting a login screen, however, once I enter any username, the connection closes and the above error is posted.