Probably a wire to one of the sensors. I hope it was a Company Shop, and you didn’t have to pay them. They should have diagnosed which wheel it was, and fixed the one wheel, sensor, wire, or whatever. Depending on which way the ecu is mounted. Blink codes will tell which one is the problem. Try turning key on, off, on, off, and on again. Count the blinks. Look underneath above the axles. Find the ecu. Note how many wires are plugged into it. 2 or 4. Also note if wires are plugged in from front side ( towards front on trailer) or plugged in from the back ( rear ) of trailer. Depending which way the ecu’s mounted will determine which side the blink codes referring to.