Spreadsheet wont save after long edits

[Step]

Cheers,

I noticed that WPS Office for Linux, latest version (wps-office_10.1.0.6757_amd64.deb) [2018-09-11] won't save when you work in a spreadsheet after long time without saving, example: "I have been working in this spreadsheet for 3-4 hours without saving it, after I save just at the end before shutting down PC or closing session in ubuntu, when I attent to reopen the archive, I noticed that nothing was saved! I've lost all changes in my spreadsheet! how bad..."

Does anyone notice or have happened this?

Thank you.