How to fix keystrokes in X11 tunnelling?

Question

I'm ssh-ing into a server environment. As long as i'm in the console, all my keys work fine. However, when I am displaying an application from the server (via X11, using ssh -XY), several keys on my keyboard don't work.

For example, the 0-key and the arrow-up key does not work in the program window.

What can I do to diagnose the problem? Is this a problem on my local computer, or on the linux machine I am sshing into?

I am using a Macbook, XQuartz and the system I'm sshing into is Fedora linux Two specific programs on Fedora which are not recognizing the keystrokes are Gedit and Matlab.

Answer 1

Restarting the server fixed the problem!

Answer 2

One way to diagnose the problem can be to run xev (remotely from the SSH tunnel, of course, tho running it locally as well can be useful to compare the results) which sometimes gives some more details about the exact events seen in response to various keyboard keys.