I am using LibreOffice Impress 7.1.2.2 on Arch Linux / Gnome and my problem is that Impress converts my vector images to blurry low resolution rastered images when changing and saving an existing .pptx file. Exporting the presentation to PDF preserves the vector images but only when the .pptx has not been closed and opened again in the meantime.
How can I get Impress to keep my vector images intact and not raster it on save?