UPD: So I noticed that few other mods don't work with locks pretty well, I think it's better to list them in one issue, as these issues have same source.

Currently discovered incompatibilities:

• Mekanism
• CarryOn

Original text:

When trying to put cardboard box on chest with lock, the lock breaks.

Tested with:
Locks: locks-1.16.5-3.0.2.jar
Mekanism: Mekanism-1.16.5-10.0.21.448.jar

@Melonslise so I noticed that CarryOn has the same issue (locks just pop off), and I think it's better to track mods with this problem in one issue.
Perhaps, something from Locks side can be done, as other mods that are used for blocks/claim protection may not have issues with said mods (testing needed).

I don't think it's a bug on my side. Mekanism doesn't check if the player can break the block via for example the BlockEvent.BreakEvent. You should submit an issue to their repo

Please see the reply from issue in their repo.

Reopen the issue on their side, I left a reply