Seems to be a routing issue in your DAW.
Don’t route the dry signal to the monitor path, only the return signal from the hardware chain.

ADI-2/4 Pro SE just plays what you throw at it.

Typical configuration would be:

Set:

• SETUP / Options / Device Mode/DSD / Basic Mode: USB

• For Class Compliant Multi-channel mode:
Unplug USB cable.
SETUP / Options / Device Mode/DSD / CC-Mode: Multichannel
Replug USB cable

• I/O / Phones Out 3/4 / Settings / Rear TRS Source: Ph.3/4,
to use the rear TRS outs as send into the hardware chain.

• Dry tracks or DAW master -> ADI-2 analog out 3/4 -> hardware chain input.
• Hardware chain output -> ADI-2 analog in -> DAW record track
• DAW record track -> DAW monitor path -> ADI-2 channel 1/2 -> monitors and/or headphones.

• Dry tracks (or DAW master) should NOT be routed to DAWs monitor path, hence ADI-2 1/2.
If this is not possible in your DAW (some insist on monitoring the master), use a DAW subgroup as sub-master for the dry tracks, routed to ADI-2 out 3/4.

There’s a quick and dirty solution, to listen to the analog hardware chain by switching ADI-2’s monitor channel’s source to “Analog”.
This works in certain configurations / “Modes” only.

In this case you need to use 1/2 for the hardware chain’s and 3/4 as monitor outputs, to separate both.
IMO this is the lesser optimum config, so not really advised.
Only if there’s no DAW for routing it makes some sense.

In general 1/2 is better suited as studio monitor output, as it can handle switching between speakers and headphones with individual settings.

What if you cut the analog mastering chain (unplug cable) - do you still hear the (dry) signal?
Then you still send the dry signal to the master/monitor section inside Ableton.

This is what you need to change.

It’s a routing thing, not directly ADI-2 related, as ADI-2 doesn’t have any internal mix function that could combine dry + wet.

Start over with a new project, just one (the dry) track.
Ignore the return input for a moment.

Now route this track to 3/4.
Does it appear on 3/4 only, or additionally goes to 1/2 too?
(On ADI-2/4’s meter overview you can watch all it’s I/O’s at the same time:
Repeatedly press Encoder 1 or 2 until you see the multi-meter screen.)

If the dry track appears at 3/4 only, add another empty track.
Configure the track for recording the hardware chain and monitor it through 1/2.

On each inter-step, check that the dry track does not appear in the monitor.

i only managed to sleep for an hour last night so am gonna get to rest. probably just going to reset it to factory settings in the morning and try to follow the instructions from the start again. hopefully that will solve the problem.

did the factory reset, changed the settings to those above

sound has disappeared completely

this is a nightmare

*edit, just to clarify:

if i set the track to out 3/4 and open a return for 1/2, there is no sound

if i leave it as out > main, then set up an external audio device with the sends 3/4 return 1/2, i am in the same predicament. the sound is there, but i cannot remove the dry signal.

i am going to hazard a guess that this is because ableton master is set to 1/2 out - but i am unaware of how to set it otherwise, as the sound just disappears completely