Hi there, check your bell settings for the channels and see if you've opted-in to receive all notifications? You may be on the default setting, which is to receive occasional notifications. Here's a guide to help check that plus your device level settings: https://goo.gl/giVA8o
I checked bell setting before doing tweet and i received as per settings which i did, problem for last 10/12 days and plm is on my fav channels which i watch regularly