When moving or copying sample with from testing set to training set, it would seem that if the sample has a label with underscore, it gets altered (ex. up_down -> up):
Thanks for reporting! Actually the label doesn’t seem copied at all, but rather infered from the sample name, so definitely a bug. Have logged it in the tracker.
Note that moving doesn’t seem to have the same heuristics. Probably better to always move anyway as it reduces the chance of having duplicate data by accident.