Dismantling an "old" container (at least any container placed before Tier 7 got released, probably even up until late september/ early october or later) will not put the content of that container in the player's inventory.
Edit: This bug only happens when you have a partially filled inventory at the moment of dismantling a storage container.
If you respawn so your inventory is empty and THEN dismantle an old storage container, this bug will not happen.
New containers will not have this issue.
Video showcasing this bug:
Note: This bug happens in both EA109075 and EX109693.