Audio Interface volume

When i use Analog Heats Audio Interface to route a signal from Ableton out (Ext. Out channel 3/4) and then route it back in (Ext. In channel 3/4) i lose around 30dB of the signal.
It doesn’t matter if the sound processing is active (same in and out volume on the level meter of the Heat) or is bypassed.

Is this normal?
Is this to give it some headroom when doing extreme modifications to the sound?