The way the meter levels are identified on the DM3 can be a little non-intuitve. The “channel” numbers for Stereo channels and outputs are in groups of 2.
For the Main Stereo Left/Right the numbers are 1 for Left, 2 for Right.
For the Stereo Input channel, again the numbers are 1 for Left, 2 for Right.
For the FX returns, FX1 Return Left is 1, FX1 Return Right is 2, FX2 Return Left is 3, FX2 Return Right is 4.
N.B. The Meter Presets in the module only made a Stereo meter for Main L/R. This has been fixed in version 3.5.8 to include stereo metering for the Stereo Input Channel (StInCh) and the 1st FX Return (FxRetCh)
See here:
