This problem occurs when the font to be used at startup is different from the font that is default in LibreOffice. A different font can occur due to a default template or due to opening a document containing such a font. If the font used by default in LibreOffice is not modified (except in Writer through Tools, Options, LibreOffice Writer, Basic Fonts, which can be changed), the problem does not occur when starting a LibreOffice application afresh without any document.
This problem occurs when the font to be used at startup is different from the font that is default in LibreOffice. A different font can occur due to a default template or due to opening a document containing such a font. If the font used by default in LibreOffice is not modified (except in Writer through Tools, Options, LibreOffice Writer, Basic Fonts, which can be changed), the problem does not occur when starting a LibreOffice application afresh without any document.