@ventus45
Kind of old news that now, given that the CVR/FDR signals can assume to have stopped and even now we're not 100% sure whether they really were picking up signals from the aircraft. Having said that, the picking up of two signals simultaneously does seem to make the stories of coincidental, similar frequency, marine beastie transponder tags seem unlikely.
As for the side scan sonar capabilities of the AUVs, that's not really a source of speculation or research in this instance. Either they find the airframe or they don't, their capabilities only limit their swath on each pass and how long it takes to cover the search area.