I’m not sure I understand exactly where you are hovering your mouse when this happens. You mention SvgKnob, but is it that big knob toward the top, or something else?
I can’t place elsewhere the small display below the tooltip. The encoder sets the volume level (it have also other features). And the mini display (indicating 50 here) is covered by the tooltip!
OK, I don’t know the answer for this, but at least I understand now. Unless somebody else jumps on this and can answer it quickly, I will look through the VCV Rack source code tomorrow and see if I can spot a way to disable the tooltip entirely.