1. You need to read the Australian addendum
https://uavionix.com/wp-content/uploads/dlm_uploads/2024/12/SkyEcho-2-Australia-Addendum-to-User-and-Installation-Guide-REV-A.pdf
2. If your mode S transponder is transmitting ADSB (ADSB-Out) you need to disable the SE2 transmit function.
3. Maybe you should go flying with the SE2 turned off - no output or input - to see what ATC, Flight Aware and FR24 see you as, without SE2 interfering.
4. Even though the SE2 transmit function should be disabled when the Smode transponder is transmitting ADSB-out you should set up the SE2 with the Hex code the same your transponder Hex code 7CBC63, your rego R2041 (drop the "19-" and add an "R" for recreational) and "1200" as the default sqark code - you dont need to change this as ATC ignores EC devices like SE2.
From Air Services https://www.airservicesaustralia.com/wp-content/uploads/FAQ_ADS-B_DEC16.pdf
"What should I enter for Flight ID (FLTID)?
You should enter EXACTLY the same characters as used in field 7 (callsign) of the Flight Notification. If you have not lodged a flight notification you should enter your registration (without the VH-). Correct use of Flight ID and other important information about transponder use is given in the AIP, Enroute, ENR 1.6 paragraph
7.1.9. Additional information is also available at:
http://www.airservicesaustralia.com/wp-content/uploads/Correct_Entry_of_FLTID.pdf
Are there particular Flight ID requirements for RAAus aircraft?
RAAus aircraft not operating under a flight notification should set their Flight ID to
Rxxxx – where xxxx are the last 4 digits of the registration mark. For example, an
aircraft registered 24-1234 should set the Flight ID to R1234 (the R standing for
“recreational”).
How can I tell if the Flight ID is correct?
There is usually a transponder control capability in the cockpit that allows entry and
readout of the Flight ID. Please consult your aircraft’s Flight Manual Supplement,
Operations Manual and/or the equipment handbook.
Why do I still need a transponder squawk code if I have set the
Flight ID?
Current ATC systems still require the four-digit transponder codes. Even in Europe
where Flight ID is mandatory, aircraft squawk a discrete Mode A code in most areas.
It is an objective to remove the requirement for a discrete four-digit transponder
code, but that cannot be pursued without upgrading existing ground systems and
while Mode A/C transponders remain in use.