I can connect to the Unattended machine but the keyboard won't type.

I can connect to the Unattended machine but the keyboard won't type.

Hi.

I had been using Assist for the past week and it has been inconsistent for me.
After a whole 4 days of no problems, now I can connect to the workstation (Centos 7) but the keyboard won't type anything in the remote box.  The mouse responds flawlessly, though, in both movement and clicks. I can click on menus and windows, select items, etc. But I still can't work because of no keyboard input.

Why does this happen?  Has anyone else encountered this?

Thanks.
Ericus