LibreOffice Calc spreadsheet slows down my mahcine

[65yl]

Hi, I recently installed CentOS 7 to replace ubuntu.

However, I found the following issue when using LibreOffice Calc spreadsheet.
When I open a .xls , or .ods file, my whole machine is slowing down, and CPU usage is high.
However, if I minimize the Libreoffice spreadsheet, it becomes normal. If I open or create a blank spreadsheet, there is also no problem.

This is really annoying. And, I could open any of my old .xls or .ods files.

Any help would be appreciated.

[lightman47]

'Shot in the dark' here - any chance that spreadsheet has circular references and is therefore always recalculating?