I’ve just found something.
The NoMachine client failed parsing your options field in the XKB configuration:
“terminate:ctrl_alt_bksp,ctrl:swapcaps”
In order to work around this issue, arrange the options so that ctrl:swapcaps becomes the first item:
“ctrl:swapcaps,terminate:ctrl_alt_bksp”
This command (client side) will do the trick:
setxkbmap -option “” -option “ctrl:swapcaps” -option “terminate:ctrl_alt_bksp“