Weird Mac login screen display

This never happened to me before. I think this is not a critical problem or something, but it bothers me every time I open up my laptop (sleep mode). The resolution doesn't fit my screen and leave a black area. The login screen is fine if I boot up the laptop, but this sometimes happens when I open my laptop from sleep mode.Does anyone know how to fix this? I hope Apple will fix this in the next macOS update.