How do I see number of or icon for unread messages?
I found out, both online and even in settings, badges go away when you swipe...Guess I'll have to resort to nova or some other launcher.

Some sources:

Source 1:
DudeThatsErin
It goes by what is in your status bar. If you swipe them away the number will disappear.
dark_sage94
They notification bar disappears for me once I read one text
LoyalRoyal18
Nova launcher does what you want, I believe.
https://www.reddit.com/r/GalaxyS9/comments/9e66n7/notifications_badge_on_icon_disappears_even/

Source 2:
Eh can't find anymore right now