Previewing SMS/texts does not "Mark Unread"

[MKV2]

[Galaxy S6 Edge, Android 5.1.1.]

Hi

I have looked for this answer all over this forum and others. Sorry if it is very basic!

• When the built-in SMS/text preview function displays the SMS on the lock screen, I can read it, but I cannot mark it read by swiping it. I have to go all the way into the built-in Messages app and read it to mark it read
• When the preview appears in the notification bar in stead, I cannot mark it read by pressing close. I have to press "View" or "Reply", again taking me all the way in to the actual app.

I am surprised that reading an SMS through these preview functions does not mark it read by default. From a user perspective, it seems quite clear that I have read them when swiping or pressing "Close" respectively. Even more so that I am unable to activate that setting.

Is it really not there?

I have been using 3rd party Messages apps on my former phone, and I think it worked well there (although the setup for both previews and the messages app was different). I don't mind using the stock app for my S6 Edge, but this setting/annoyance really makes me consider.

How have the rest of you set it up?

Thanks