Multiclass argument removes annotations from images

[junior-senior]

I have a dataset that has multiple classes of objects within each images. I used the multiclass argument in the command line to separate an annotation file into training and testing and found that using this argument led to images having some annotations removed, for example, an image that had 7 annotations originally only had 4 in the output. I don't know if this is the desired behaviour, but this is not good because say during testing the model segmented and classified 7/7 objects correctly, the labels would say 3 of these were incorrect.