Gxmessage -geometry switch not working

When I run this on a TV that is used in place of a monitor, I get a full window instead of the specified geometry.

That switch used to work with my Acer monitor.

gxmessage -fg red -font 'sans 50' -timeout 3 -geometry 100x100 'testing 123'

Using any 2 values for geometry always results in a full window being displayed instead of one that is 100x100.

Is there a workaround?