Welcome @vetalinesantana!
You may want to consult the UNITE website and article for more details, but my understanding is that the "dynamic" classifier clusters different species at different % similarity thresholds, based on manual curation by taxonomic experts, as opposed to a single % identity to define species.
So it is not unusual or unexpected that dynamic would yield different results from the 99% OTUs. The question you need to ask yourself is: which do you trust? Do you find M. canis or M. audouinii more believable?
Short of having ground truth data that you can test, you might not be able to determine which is more accurate. We have actually tested these databases recently, and the clustering threshold had less impact than other factors... in fact, 99% and dynamic yielded very similar performance... so I cannot say that one stands out as more accurate.
Good luck deciding!