External motion sensor not sending notifications

Howdy, I’m looking for a little help. I recently purchased a bridge and 2 external motion sensors for the sole purpose of being able to be alerted if someone or something were to enter my driveway. I have the bridge and external sensor units setup. In the app I can see when the motion sensors are detecting motion, so they work, but I do not receive a push notification from the app (on iPhone). Motion detection is enabled, push notifications are enabled. App is up to date and I’ve tried logging out and in again. IFTTT doesn’t recognise smart lighting sensors as a category from which to trigger a sequence. Can anyone advise as to what might be my issue and why I receive no notification on motion? Many thanks