Vino-server numpad won't work in VNC mode

[Monnom]

I installed Ubuntu 22.04 and enabled remote desktop in VNC mode (vino-server). I connect from other machines (Ubuntu and Windows) and the numeric keypad does not work when NUMLOCK is activated (when it should type numbers).

When NUMLOCK is disabled on the observer station, the numeric keypad works, i.e. 4="left arrow", 3="page down", etc.

This problem is identical regardless of the VNC client I use (TigerVNC, Remmina, gvncviewer, UltraVNC for Windows) and the OS of the observer station (Ubuntu 18.04, 22.04, Windows 10).

Three diagnostic points.

- Point 1:
* On the observed station I run the “screenkey” command
* On the observer station I type "b"
* On the station observed I see "Num.Lock(off) b Num.Lock(on)" (it does it with each key pressed)

- Point 2: the problem arises with the default window manager of Ubuntu and Xfce.

- Point 3: for comparison, on an Ubuntu 18.04 machine with remote desktop in VNC mode (vino-server), the numeric keypad works fine.

So to summarize, I enabled remote desktop on my machines:
2 Ubuntu 22.04 machines where the numpad does not work
1 Ubuntu 18.04 machine where the numpad works fine. (Windows 10 machine is a VirtualBox VM on Ubuntu 22.04)

Any idea ?