An afterimage remains in uploaded spreadsheet which have fronzen rows

[ultrakanji]

The problem could be reproduce in spreadsheet demo site (Upload Excel files) and also local development environment.

Problem:

• cells just under frozen row are hidden by white space, though cells have correct values
• when scroll up and down in sheet, the afterimage remains top of the sheet, especially merged cell

Conditions:

• upload sheet have frozen rows
• upload sheet have many rows (it was not reproduced in little rows sheet)

This problem occurred in both Chrome and MS Edge.

I attach sample book which reproduce problem and a screen shot.

sample book: sample_wrong.xlsx

screen shot: