CTRL meta key 'sticky' in GUIs over X11 forwarding from CentOS to fedora

CTRL meta key 'sticky' in GUIs over X11 forwarding from CentOS to fedora

Despite numerous problems, I managed to get X11 forwarding working from a
SSH server running on a CentOS host to a Fedora client (changing various
settings and finally fixing it by installing a package for
authentication). The program in question is Geany. It acts as though the
CTRL meta key was always pressed, not allowing me to enter characters
normally.
What can I do about this?
What information should I provide?
Here is exactly what I mean:
ssh -XY4 -i ... user@host
geany
Within Geany every keystroke is processed as if with the CTRL modifier.