Cross-iframe component reuse causes drag failure

Software version (please complete the following information):

• Browser [ chrome ]
• Vue Version [*]
• vue-grid-layout Version: [*]

Describe the bug In special cases where components need to be reused across iframes, it may cause dragging anomalies

To Reproduce https://codesandbox.io/p/github/fuzi1996/vue-gird-layout-example/master