I have the mx3 sparrow with 4 in 1 esc 28A and I switched the original PBF3 Evo F3 with the HGLRC XJB OMF4 but I’m not sure if it’s the right one because the drone only powers up while connected via USB and when I connect only battery it doesn’t power up .
Sounds like you FC it’s getting power from the 4in1…
Double check you connections and pin outs