How do i stopped a shared user smuggling someone in the house?

We Love ring doorbell. We have used one so our own home location and also my elderly mother’s.
I’ve read a few threads on here and have noticed many of the replies from staff, keep switching to a Ring Alarm device, when people have specifically enquire about the Doorbell…?
Our issue is that our youngest daughter has a very shifty boyfriend, who knows how to avoid being detected on the video.
How does he do this and more importantly, how do we resolve it? As i can’t figure out a way on the settings. Fyi, this is a Ring 3 (battery).
Appreciate Any help as this is stressing out my wife!

Hi @Gazzapen. This really isn’t a concern we have enough information to be able to assist with. If your doorbell is online, and you have your Motion Settings optimized, there is not a way to avoid detection. If there doorbell is not detecting anyone, then perhaps the shifty boyfriend is entering from somewhere else.