If your game crashes while saving, or if your PC shuts down unexpectedly, you might end up with a corrupt local file. When you next launch the game on a different PC (or even the same one), Steam might download that corrupt file from the cloud, overwriting your potential backup.
If you are moving between two PCs :
On Windows, your save files are not located in the "Documents" folder. Instead, they are tucked away in your . resident evil 4 remake save data pc