Rekordbox Trim Not Working when using DDJ-200 with aggregate audio

Hi.

I'm using DDJ-200 with Rekordbox on Mac, with external soundcard for headphone monitoring (cue), and Mac internal speaker for master output

Naturally, on a Mac you must setup aggregate audio to combine this two soundcard

The problem is I cannot control the trim level/ knob on Rekordbox when using the aggregate audio.

Also the audio level is so loud by default, making the sound clipped.

Strangely, when I use Mac speaker for output (not using aggregate), the audio level seems fine and I can control the trim knob.

Here's the audio level looks like when I transfer the recording file to Final Cut:

The loud audio level when using aggregate audio (full most of the time):

Is this a known issue? I'm quite frustrated because the recording sounds kinda terrible.

I can use mid & low EQ to lower the sound level, but this just not convenience to use..

Thank you