When re-opening files, Musescore changes untied notes to tied ones

I am writing a score in which I have selected the option to display note values across measure boundaries because I am transcribing non-metered music. I did this because I do not want tied notes. Musescore 4 obliges, but when I save and re-open the file, Musescore 4 decides to randomly change one of the notes that goes across measure boundaries into a tied one. Not all, and not the same one each time. It is quite frustrating and wondered if there is a fix for this.