[intrepidneo]

Before, whenever a message notification came on the phone, it would display details of the message (even though for a very short time). This was helpful as you would know (without even opening the message) what the message is about. However after recent ui update, this is not the case anymore. You see the message icon in the home page & you need to click on this to see the message.
The same applies to missed calls as well.

[CJLB]

Yes I've got this happening now after updating at the weekend. It's annoying as previously it was useful to take a quick glance at the screen. I've looked and tried all the settings and there doesn't seem to be a way to make that happen anymore.

[dougm1970]

just came in here to post that very question

[mark7914]

Might be a security fix.

Ever watched "Hunted" on TV?

All someone who has stolen your phone and knows your common passwords needs do is try to log in to something that requires them to key in a code sent to your mobile.

If you leave the preview set to on, they don't even need to unlock the phone, which will happily show them the code in the preview.

Convenient as it may be to have the preview, it's a serious security risk to leave it enabled.

On my S8 this was enabled by default but I turned it off for that reason.

Lock Screen and Security > Click on Notifications > Enable/Disable "Hide Content"