Create a Box in Front ortho view, Object Orientation not match World orientation

When I try to create a Box within the front orthographic viewport, the box's object orientation is not aligned with the world orientation.
As in X, Y and Z now are different.

Creating the box within Perspective viewport, the Box Object and World orientations are the same.

For practical purposes, i am trying to trace around a Background viewport image in front viewport which I will also manipulate in the other viewports to further define the shape.

I'm not sure if this is a bug or expected behaviour?

Many Thanks.

It's not a bug. You can use this command to align the object's pivot orientation to world, Geometry > Common Command n Tools > Freeze Object Orientation.

Thanks for that, now my orientation is correct again.

I'm curious why the orientation is flipped about?

It is just in case it may be useful in some cases.
You can also use the "Object Pivot" tool to set object's orientation. At 6:47, https://youtu.be/yuCPC_OShRY.