I cannot use keyboard in VM on Ubuntu 20.04.2 and tightvncserver server via vnc

I have some issues with VNC configuration. So, I will describe issue.

1. I have Wolfpass server with installed Ubuntu 20.04.2, I installed this OS this week, and Only what I did is proxy configuration, IP configuration and install quemu Virtual Machine Manager.
2. I installed tightvncserver and xfce4 on server and I'am using vnc connection to it with moba xterm or vnc viewer tools.
3. I create VM with CentOS 3.9 on VMM and I tried to use keyboard in CentOS terminal, but keyboard is not working.
4. Strange thing is fact that keyboard work ideally on Ubuntu 20.04.2 native OS, but not in quemu VMs.

I tried many configurations of tightvncserver xstartup file and with gnome or xfce4 desktop environments, but it doesn't work.

Next strange thing is fact that keyboard works on CentOS when somebody works on it in lab connected with connected mouse, keyboard and VGA to wolfpass ubuntu server directly.

I waste 2 days of debugging it and I cannot find solution. Before reinstall Ubuntu server I Have this server configured by someone else with a lot of Ubuntu, centos, and other OS based VMs, but I have the same issue, I reinstalled it, because I thought that can help.

Please help me with that issue

I tried with xstartup file configurationsm but not all allows me to log in to VNC due to grey screen on Gnome session.

gnome (didn't work)

#!/bin/sh

# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc
gnome-session &

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
#xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#twm &

oryginal (didn't work)

#!/bin/sh

xrdb $HOME/.Xresources
xsetroot -solid grey
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession

xfce (works)

#!/bin/bash
xrdb $HOME/.Xresources
startxfce4 &


gnome_v2 (didn't work)

#!/bin/sh

xrdb $HOME/.Xresources
xsetroot -solid grey
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession


original_gnome_v2 (vnc works)


#!/bin/sh

xrdb $HOME/.Xresources
xsetroot -solid grey
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession
gnome-panel &
gnome-settings-daemon &
metacity &
nautilus &