Unable to answer with app

I’ve installed the Ring app on my iPhone 6, I get motion notifications and I can do live views no problem. But when my mum came today we tested the doorbell side of it with me answering on my phone. It came up on the app with a picture of my mum, and the green banner stating Answering, but when I press on it, nothing happens. What am I doing wrong? Or is there something else going on? Thanks for any help given.

Hi: I wonder if your signal strength is low. What does the RSSI value show on Device Health under Devices? Don’t pay attention to the negative sign. The lower the number the better. Ring says less than 40 is basically optimal, between 41 and 65 sufficient, but above 66 is critical.