Expandable p tag does not expands as expecting manner while copy pasting the content

Question

I have a contenteditable p tag which expands til a particular height and then it will have a scrollbar. When copy pasting the content inside that expandable p tag it does not expand or sometimes it will expands beyond the height limit.

HTML:

<p contenteditable = true id = "expand" class = "editable">

CSS:

     .editable{
         min-height: 60px;
         ...
     }