joystick icon does not show on traditionnal editor

all the rest of the plugin works well, including the wizard, but the icon does not show in the backend post editor, rendering most of the plugin 75% useless so far.

latest wordpress 6.0.3

Setting is traditionnal editor, as many I hate the block/gutemberg editor (if that is the cause; not sure, as that would be the first time I hear a plugin is not working because of that)
Thanks,