Thanks for being with Samsung and sharing your concern. We would like to inform you that it is default feature of the device as once an app is unlocked, it will remain unlocked until the screen turns off. Please know that we are continuously working to improve the Samsung customer experience, and we have taken your feedback into consideration. We want to improve Samsung so it serves your needs and is the best product it can be. If you have any other suggestions you would like to share with our product team, please let us know. Your comments and requests are greatly appreciated. We appreciate you taking the time to share your ideas. 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#/
