I've been getting notifications issues as well, with snapchat I've noticed this instantly. I don't get notifications until I open the app. Other texting apps are the same, I haven't found a setting that will make it show my notifications. I thought maybe the "remove permissions if app is unused" would be the culprit but after changing it I would still not get notifications when out of the app so here I am making this reply cause people are having the same issue
