Motion detector in disarmed mode

1st post on here so any help would be much appreciated. I’ve recently set up my ring alarm system with 2 motion detectors and 2 contact sensors. However, when disarming the alarm when entering my property from away mode one of the contact sensors still sets off the alarm when I enter the room it’s located in, even though I’ve disarmed the alarm on the keypad when entering the property. I then have to quickly disarm it again on my phone when the notification comes up in order to stop the alarm sounding. Does anyone known if this is simply user error on my part of a glitch in the system? Many thanks