I checked the algorithm against your device addresses and it seems to be fine so I'm not sure what's causing your problem.
As for the 7A:4D:5:1:8:0, it should be 7A:4D:05:01:08:00. This is just a result of the Serial.Print function discarding the leading 0 for each byte. It's not a problem.
I don't know what else to do about your problem except for you to avoid using the search function and just address all the devices on the bus individually.