When you power up the ClariVUE10 sensor, we’ve found that it take a few seconds to warm up before the Mayfly can “see” it. So when that sketch cycles through all of the available numbers and letters, it usually doesn’t see the ClariVUE until the second loop through.
So when you first connect the sensor from the factory and run the sketch, it’ll run through one full loop before finding it on address “0”. Then you can either leave it there or enter another address, in your case “2”. Then it should go through the loop check again and say that it found the sensor on address “2”. If you run that sketch at any time or the “c_check_all_addresses” sketch, it should always find the sensor at address 2. If that’s all correct, then the issue is just with your logging sketch. You can post it here if you want, just be sure to edit out any personal information like UUIDs or wifi APN info.