Is it a USB drive -- or is there any reason you can think of why the mount might not always be available?
From your screenshot:
The fact that this folder has been modified in the last 9 days suggests a possible problem. These keys are static.
Here's mine for comparison:
Note, that my adb folder hasn't been modified in over a year.
What do the Accessed, Modified and Created dates look like for the 3 files in the adb folder? There's only one that should show being modified since you set things up. These are the two that shouldn't have changed: