Did you initially receive your songbird air drop on uphold? If so go to the transactions page and find that transaction and open it up to see the details. Maybe the details of the receiver (you) are on it. Did you transfer from uphold to Bifrost. Maybe in Bifrost you can find the transaction and see who the sender address (you) was
Is there any way you can go to the withdraw/deposit assets page and click deposit to see? That's how I get my address at bitrue. i don't use uphold tho so I don't know its characteristics/functions.