Controlling custom tooltip positioning

I found this related post: Control anchor position of a tooltip widget?
But the solution provided there doesn’t seem to work and I didn’t wanna necro-post.

With a custom tooltip it always uses the mouse as the top left anchor point, like this:

But I would like to control it so the tooltip is always in a static place relative to the owning widget, like this:

No matter where I put my mouse, it’ll always be centered to the parent widget.

I can’t seem to find any methods to actually determine where to position the tooltip, so any guidance is welcome!