Remote VM, accessed via X2GO, receiving input signals over and over again. How to fix this?

When I type 'c', for example, 'ccccccc' comes out. So this is annoying. Should I decrease or increase some settings, on the VM or X2GO?

My local station settings:

OS Slackware 14.2
RAM 4GB
bash-4.3$ glxinfo | egrep -i 'device|memory'
Device: Mesa DRI Intel(R) Ivybridge Mobile (0x166)
Video memory: 1536MB
Unified memory: yes
bash-4.3$ lscpu
Arquitetura: x86_64
Modo(s) operacional da CPU:32-bit, 64-bit
Ordem dos bytes: Little Endian
CPU(s): 4
Lista de CPU(s) on-line:0-3
Thread(s) per nucleo 2
Nucleo(s) por soquete:2
Soquete(s): 1
ID de fornecedor: GenuineIntel
Familia da CPU: 6
Modelo: 58
Nome do modelo: Intel(R) Core(TM) i5-3337U CPU @ 1.80GHz
Step: 9
CPU MHz: 2048.132
CPU MHz max.: 2700,0000
CPU MHz min.: 800,0000
Wifi Internet Speed: 100Mbps

X2GO Session Settings:
Desktop XFCE
Connection:
LAN
XFCE
16m-jpeg
Image quality 9
800X600

Remote X2GO Server:
OS Ubuntu 18.04.4 LTS
RAM 65G
glxinfo | egrep -i 'device|memory'
Device: llvmpipe (LLVM 9.0, 256 bits) (0xffffffff)
Video memory: 64374MB
Unified memory: no
Ethernet Speed: 1Gbps

VM remote on X2GO Server:
OS Slackware 14.2
RAM 6GB
Video Graphic 128MB