WPS Office Writer writes extra characters when typing, how to deal with?

Question

Text editors

Maybe someone had such nonsense? Moreover, the investigation revealed that these characters come out when typing, only if the document is not saved. Maybe some problems with writing to a temporary file? Or I don't even know what else it could be. In principle, immediately saving a document is not a big problem, but it shouldn’t be like that, in other offices everything is OK.
WPS Office is the latest version to date, Windows 10.