Samsung has sneakily made us enable the s h i tty ad-ridden Wallpaper services on M30s and other devices after July Update without any prior notice.
These services use Mobile Data and other data collected from your smartphone usage to target ads on lockscreen thereby draining your battery and even affecting performance.
To disable them- go to "Settings > Lock screen > Wallpaper services and then select "None".
Your lockscreen will now be back to normal and notifications appear as it is.
