This thread is coming up on almost a year old and from the number of posts, clearly this is still an issue for us. I am relatively new to Ring as we moved into our new house in June and I installed a Ring doorbell which works well once I got the zones tweaked and have People Only mode enabled.
I have turned on People Only mode on my Stick Up Cam Elite that hangs from the ceiling in my screened lanai. Since we live in FL, there is no shortage of spiders and small flying instects that find their way into the screened lanai. I have the Ring cameras integrated with Alexa so we are frequently woken up in the middle of the night with Alexa saying “motion detected at the lanai”. People Only mode appears to be pretty useless and my plans to rely on the cameras for home security are now in question. I even tried turning People Only mode off and setting the sensitivity as low as it goes but still got woken up in the middle of the night. 
The lanai camera has alerted on small gnats flying up to the camera, a spider descending a web filament and just a single web filament blowing in front of the camera.
Come on Ring, we need a fix for this so that we can all get a good night’s sleep!
Here are some examples if it helps:
https://ring.com/share/33842cf4-a3ee-4164-9e17-187945442053