Problem Description:

When pasting a merged cell to another sheet, this will cause a mess of grid lines.

Reproducing Steps:

1. displaying attached Excel file within Spreadsheet
1. copy ""drag move"" and a merged cell (A7:B7) from ""cell-text"" sheet to ""blank"" sheet
2. select ""cell-text"" sheet and select back to ""blank"" sheet
3. increase a row's height with mouse dragging.
expected:

Actual:
you can see grid lines is in a mess.