Grid Minor does not work with graphics_toolkit('gnuplot')

I switched my Ubuntu 20.04 from TWM to Gnome because google-earth-pro 
did not display pictures with TWM.  It does with Gnome.

I kind-of do not like Gnome.  Maybe that is just getting used to a new 
interface???

I believe 'grid minor' stopped working with graphics_toolkit('gnuplot'), 
which I have set in .octaverc since Jan 6 2020.

octave:1> x=linspace(-2*pi,2*pi,10000);
octave:2> plot(x,sin(x))
octave:3> grid minor on
No grid.
octave:4> grid
Now, I have grid.
octave:5> graphics_toolkit()
ans = gnuplot

octave:6> graphics_tooklkit('qt')
octave:7> plot(x,sin(x))
octave:8> grid minor
Now, I have grid.

octave:9> ver
---------------------------------------------------------------------
GNU Octave Version: 6.2.1 (hg id: 0e734bdfd6b2)
GNU Octave License: GNU General Public License
Operating System: Linux 5.4.0-72-generic #80-Ubuntu SMP Mon Apr 12 
17:35:00 UTC 2021 x86_64
----------------------------------------------------------------------
<snip>

I am missing something.  What?

Tom Dean