I have found since version 3.6, when you send the sliced file to your SD card etc, you cannot overwrite the file. At times I have realized that a part was not correct, and re-sliced the model and re-saved it to my SD card. The issue or bug is that the original file is not overwritten. This means when you start the print, changes made after the first "version" are not picked up by the file. I think it should be a simple code change similar to how MS Windows overwrites the file, with a warning message that your about to overwrite the file.
I have used the 4.5.0 beta since its release, and found it to be an improvement over earlier versions, and this code change will save a lot of problems for new users as well.
Appreciate any feedback if there is already a way to resolve this.