Why is the first label always lost on move during model inference

[S_X]

I noticed that the detection box of the first label has one more number in the lower left corner than the others, is this the reason? I moved all the tags back one place for my model and added an unused tag to the first one, and the other detections no longer looked sluggish, but there were times when there were obvious detection errors, and when displayed, the detection boxes of multiple labels overlapped and always showed 88% confidence, which really bothered me for a long time