I have a Ring Stickup Camera that will not pick up my cat walking in front of it unless the cat walks up to the camera within 6 inches and looks directly into it. I have the motion setting set to the max sensitivity and have adjusted the field of motion detection from narrow to wide as well as placing the camera from distances of 2 ft to 10 feet from her food bowl trying to capture her at the bowl. My Ring Flood Light Camera will pick up a cat at 20 ft away. I about to think the Stickup Camera is bad.
If you go into your motion settings it has a setting that makes it so your camera won’t pickup animals or movement that isn’t a person in its range of view. This is so you don’t have the problem of your camera constantly going off every time a squirrel goes by or the wind blows and tree branches are swaying in it’s view. That’s my best guess as far as solving your issue