Dell Monitor S3221QS compatibility issues

Hey, I am having issues with connecting my xbox one s to my dell monitor through HDMI. It initially was showing a black screen. But I changed the resolution setting on my xbox to 720p. Now, it randomly disconnects for 1-2 seconds even when I'm not playing any games. I've tried 4 different HDMI cables provided with my xbox and dell monitor. It just doesn't seem to work. My internet and everything is fine. The monitor even connects with my laptop well. Its just the xbox one s I can't seem to figure out. Please help....