Weird change in my Galaxy S9 lock screen behavior

[PacificaBren]

This bizarre: Today my S9 began not consistently asking me to enter my PIN to unlock the screen. I went through my lock screen settings and changed it to ask me to enter my PIN just five minutes after the screen shuts down, but...

It seems like the phone can be in my pocket for way longer than that, yet the phone still doesn't ask for my PIN.

Note I am not using any settings that would prevent the phone from locking when it senses it's near my body or close to a trusted device in my home.

Is there an app or a system app whose cache I need to delete?

Or some other setting I should be looking at?

Thank you!

 

[AugieTN]

Have you rebooted your phone?

Is the screen pointed towards your body or away from your body when it's in your pocket? Pointing the screen away from your body when it's in your pocket seems to cause fewer problems.

Your phone is about 6 years old, A factory reset may help