For me, no heating, plugged in without peripherals.

It warms up when charged, in proportion to the power delivered. If connected without load, however, it remains cold.
If yours heats up 'with no load', it means it is defective. I recommend you have it replaced.

If no appliance is connected, mine stays cold. If a load is connected, the block can get very warm, but in my opinion this is normal.
The fact that it gets warm without a load is not good, could be a short circuit in part of the power electronics.

Replacement would certainly be recommended 😅