Notifications not working Xperia L3

[Mutak94]

Hi

A few days ago I manually switched off notifications for messages in several apps: Facebook Messenger, Facebook Pages Manager, WhatsApp and the stock SMS app. This was only necessary for a short period of time and after that I turned those notifications back on.

However, sometning went wrong apparently, since I'm no longer getting notification sounds for these apps. The notification appears in the bar, but with no sound. I checked all possible notification settings and everything is turned on. Also, I'm getting normal notifications with sounds for all other apps.

I tried reinstalling WhatsApp, but the problem persisted even after that. What can I do to fix this problem? When I go to notification settings of either of these apps, at the bottom I can see the text "1 category deleted". I did some googling and I found out that this means that Android automatically deleted some notification categories - this is a feature intended to prevent spamming. However, in my case I think that Android is wrongly detecting those categories as spam and deleting them automatically, which is why I'm getting no sound.

I have Sony Xperia L3 with Android Oreo.

 

[mopages]

So it's not likely to be because of the deleted category. (Sorry if stating the obvious but please confirm that your phone doesn't have Do Not Disturb mode enabled).
How did you manually switch off the notifications, did you do it from within each app's settings, or from your phone's Settings > Notifications, or was it Apps > App Settings > Notifications?