How do you remove a package during the pick/pack/ship process? Remove items from boxes?

Very new to this system so sorry for the dumb questions.

I am packing a multi-box order and some how mid-packing the package got processed and I ended up starting a 3rd box. My bad.

1- How do I remove product from the extra box, I tried the remove button but it keeps jumping to a different box and telling me No since the product is not in that box

2- how do I remove the extra box, it is showing 3 when I only have 2.

3- Is it possible to remove the box and ‘dump’ the contents in one move.

Our old system had ‘unpack box’ and ‘remove box’ buttons.

Thanks