With the jump to MIUI 12 or even starting from MIUI 12, some smartphones have encountered apps that are not optimized to respond from Xiaomi notifications . This drawback breaks one of the greatest advantages of Android and prevents you from taking advantage of it, although it can be easily fixed.
Solution
Whichever app is causing the problem, we are just going to have to change the style of the notifications in MIUI 12 . This process will change the aesthetics of the notification and in turn will allow us to respond or mark any notification as read. You just have to go into Settings> Notifications> Notification bar and switch between MIUI or Android.