I had a problem calibrating the compass at the weekend. I'd gone to a spot I'd flown at before but the app displayed a compass error and prompted me to recalibrate. I had umpteen goes at this, moving large distances between each attempt and eventually changed the battery as it had gone down to 59%. The repeating error had warned of high electromagnetic interference and when I changed the battery it struck me that maybe my new Rewire T102 GPS tracker (attached to the legs) was causing the problem. I took it off and the drone calibrated fine. What I don't know is: was it the battery swap or the GPS removal that fixed it (or neither)? Anyone else have any compass problems with a tracker mounted?