The edge lighting doesn't work when used as when screen is off. For example it won't work for WhatsApp notifications, it would only work for phone and messages.
Thank you for reaching out to the Samsung community! We would like to inform you that it is the default feature of the device. Edge lighting notification will only work for Samsung default applications when the screen is off.
Be sure to hit ♡ when you find an answer that works for you. For Further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/
