I have an Acer T07 (aka Liquid Zest 4G aka z528) with Android 6.0. I got it for Christmas so I did not have the time to tweak it for now !
Whenever I recieve an SMS, a notification does show up, and then disappears after half a second. This is particularily annoying since I am not always looking at my phone and when I check it I see no notification. Then, I open the SMS app (currently using Pulse SMS but the same happened with Textra and basically any alternative SMS app - tried a lot of them) and see unread messages I was not aware of. However this problem doesn't happen with the stock SMS app.
I thought this was just with SMSs but from time to time the phone vibrates and when I turn on the screen to see what's hapening, I see nothing - which is certainly because a notification arrived just to immediately disappear.
I don't have a list of the application that do this mostly because I never see those notifications. Apart from SMS, I use very few apps that generate notifications (no social networks or similar apps) so it's hard to tell how many apps have the problem and what they have in common.
I found no one with the same problem by googling it and neither by searching this SE.
Any help on how to fix this weird problem is highly appreciated !
EDIT : I found out that Discord app does it as well. I also found out that some notifications don't even show up, but just make the phone vibrate without letting me know at all what app it comes from.