I tried to make a bank using a custom named item being placed in a specific slot, which triggers other things when moved from it's slot. It works fine the first time, but afterwards it doesn't activate or do anything. It says in the command blocks text thingy, that it had successfully replaced a item in a slot. This seems to work fine with normal items. If you change item, it'll work the first time, but the same thing happens afterwards.

I tried using a fill and a hopper clock but the same thing happens.

Step 1: Create a clock.
Step 2: Add a command with the /replaceitem command.
Step 3: the item must have a custom name.
Step 4: It should fail after the first time.