File name automatically changes when I'm using PowerPoint

As a tutor I create a lot of Powerpoints on my HP Windows 11 laptop. However, when I open them to edit them my laptop automatically creates a new duplicate file with the same name followed by LAPTOP and a number on the Desktop or changes the file name to a number. This is causing problems as I'm then not sure which is the correct version of the file and have to delete the duplicates. Why is it doing this?