Why does Impress alter my table whenever I save in Microsoft format when I open it back up?

I make a table in Impress, then I save it in Microsoft PowerPoint format and then when I open it again, the table has been radically altered (some of the titles are missing and the cell formats are messed up). This is highly frustrating and aggravating, because I don’t understand why the option “save in Microsoft format” exists if it doesn’t actually save, it alters and deletes information.
Don’t advertise things your software can’t do

You write on ask.libreoffice. Here users help other users. Your frustration is understandable. Write a letter to The Document Foundation with your request. It’s no use here.

Why not save as OpenDocumentFormat. Word from Word2007 up to the latest versions can open, edit and save in this format. Unfortunately (deliberately) Microsoft Office does not create the same result in code. And reverse engineering is not allowed. Try out other office apps like WPS office or Softmaker Office if they are better.

Saving as the Microsoft PowerPoint format brings you the warning dialog about the possible data loss. Where is it “advertised” that the support for foreign formats is complete? If user does not read documentation on the software that tells about it every time, and ignores warnings that tell about it, then the user is responsible for own actions. The option to use partially-supported foreign format exists for those who really need that, and who reads and understands docs and warnings.