Low resolution on imported files

This is a recent problem I've been faced with, it's incredibly annoying and I don't know how to fix it. But basically, everytime I import in a file to work on, its resolution is instantly lowered pretty drastically. I have this habit of exporting my files after I've done a certain amount of progress and then importing it again to keep working on it if that makes sense (I prefer working on a single layer and with the app's tendency to corrupt my files, I prefer working this way to save my progress)

Does anyone know a way I could fix this??