Many posts written about this topic.
The solution that will work is to add a keyboard mapping on the host machine that you will connect to.
This new keyboard layout must be the only keyboard layout on the system. If another keyboard layout is in the list you will want to remove it as it may be the cause of the issues.
Once your client and host both have the same keyboard layouts installed you will need to end your x2go session and restart it for the keyboard mapping to take effect.