After placing some items in a barrel, I looted the nearest small town. Upon coming back to the barrel about 15-20 minutes later, I found that two items looked like they were missing. I first though that someone had followed me and taken them, but the slots that those items occupied cannot be interacted with any capacity. I cannot move items into those slots. They appear to still be occupied, even though the icons are missing. I have marked the slots that appear to be bugged in the provided photo.

EDIT: After I left the area, logged out for a bit, and then eventually made my way back to the barrel, both the .308 and the shotgun shells reappeared. {F32333}