If you get error in BLHeliSuite “Found 2 ESC with similar unique ID numbers”, here are the possible causes and solutions.
#1 Signal Wires Shorted
ESC signal wires are shorted/touching each other.
If you are using standalone (separate) ESC’s, check ESC signal with a multimeter to confirm (in continuity mode). If you are using 4in1 ESC, check the header pin connector, and make sure the pins are not bent and shorted.
#2 Motor Remapping
Wrong motor remap config. Try to reset resource for the motor pins and try again.
#3 Motor Signal Shorted to Frame
It’s possible that your ESC signal might have shorted to the carbon fibre frame, or metal standoff.