100%, like @K6CCC stated, check your rules. What rules to do you use?
Also, if your app is slow to connect to the camera, make sure you are fully connected to the live stream before you enter the cameras settings. If you go into settings before they can be populated correctly, it MAY show that your motion detection/notifications is disabled, when in fact it hasn’t populated and per the cloud they are enabled.
Another note, enabling and disabling “detects motion” also controls if you get notifications or not. No cloud events, then nothing to notify you of. So if your normal practice is to enable and disable detection and notifications together, just enable and disable detect motion and leave the notification settings enabled. Simplify your stuff.