BB Hub is not showing my social media accounts on Android (Google Pixel)

My email accounts show up fine in BB Hub, but FB, Twitter, Instagram, etc. don't. The logo for each of these DOES appear in the list of accounts, but the counter of messages stays at zero.
(OBS: the Google tray in the idle screen DOES show these accounts).
Hub gives a message:
"To see messages from your social and instant messaging accounts, please turn on notification access for BlackBerry Hub+ Services.
Go to your device settings. Tap Sound & Notification > Notification access, and turn on the BlackBerry Hub+ Services Switch".

Now, if I go to the notification settings, I CAN choose for BB Hub+ (and any other app) which notifications it is allowed to SEND, but I CAN'T find how to make BB Hub+ "pull" notifications from other apps.