I must first point out that this is not a bug, but an implementation problem that can result in "bugs" if the physics behavior is used in specific ways.
The physics behavior is scaled by a constant worldscale, making the behavior good for objects from 5px to 500px. Box2d has this range limitation, but the scale that it is attached to construct2 can be different. For example, the behavior could work well for objects from 10px to 1000px.
Setting the scale rigidly from within the behavior isn't the best solution unless simplicity and one size fits all is important (which it probably is lol). In a low res pixel game, the limitation is perfectly fine... unless you want a 4 by 4 fireball bouncing around. But in a hires game it's really easy to have objects larger than 500x500. In the past, I have gotten around this simply by scaling all the sprites down, but then you have to have a smaller canvas size... In other projects, I have simply gone into the behavior and changed the worldscale constant. I have to remember to change it during work with other projects and make sure I export it with the correct settings.
My work around works well, but I wouldn't expect the average user to have that option. At the same time I don't think that the average user ever cares about this 5px to 500px limitation. Or they assume that its set in stone and can't be changed.
I probably wouldn't change it but maybe it should be?
Either way... I thought I would bring this to your attention.