unexpected layout beheavior

[nileblack]

Software version (please complete the following information):

• vue-grid-layout Version: [e.g. 2.3.12]

Describe the bug
A clear and concise description of what the bug is.

Please use the CodeSandbox Template to demonstrate your bug. It is much easier for us to help you if you do.

Expected behavior
block 19 should not move above block 0

Screenshots