Garmin Edge records a speed of almost constantly 209 km/h from Elite Justo 2

You must write 218mm as wheel circumference in the Edge under Justo sensor details. (because now i assume it is on 2095 or similar valid 29" circumference but the Elite trainers have such an idiot numbers, and different model by model..., honestly , i dont understand why dont they modify it internally avoiding such an issues...)

probably you need to write this value in the MyETraining app also to the right submenu (circumference for 3rd party apps and devices) to avoiding the value mismatch and overwriting