Because Samsung changed how storage are shown starting with OneUI 6.0 to make it more clearer

I have the same problem. But I’m 90% know why.

The adhesive for the glass will wear out overtime, but will accelerate with addition of heat. I usually use my phone for navigation + placing it directly on my windshield. Hence, my adhesive wear out a lot faster.

This is exactly the thing I noticed for a while too. I noticed it on my old Xiaomi Mi 9T as well as my current phone.

I think its because (and this is just a theory) apps have lower security requirements than the lock screen, since if you’re already unlock your phone, then it probably still you making payments in your banking apps.