Thanks for response... This is helpful. Pls if anyone knows a simplified way to check address, pls provide a link or instructions as I'd feel better about this confirming the address for output #2 (at least for the first time).  Much appreciated.

Thanks for instructions, but I am pretty new to all this and half of what you said a way beyond me. Even if I somehow managed to translate and complete the steps I don't understand why only now after dealing with the Hashflare site did this situation occure. In all other transaction, all of which had "change" left over in my account, never was the transactions presented in such a way.

Yes, I reported it to Ledger wallet support. The email confirmation that they received my concern said 1-3 weeks for  response. I can't think of any purpose for Ledger to have a setting that would do what was described above. Sorry if situation isn't clear, don't know how else to explain it.

My first post, new member...
Two days ago I tried to buy into the cloud mining pool Hashflare. When I tried to purchase with Bitcoin (held in my ledger Nano S) I noticed something strange. My device was asking me to confirm "output #1" with the correct btc amount and address (i thought this strange, as I've never seen "output #1" before when moving btc, but because the amount and address we're correct I confirmed the transaction. Then right after the device said "output #2" (very scary) with a btc amount equal to what would be the remaining amount in my account and the address was not known to me. I did rejected that confirmation and the entire order failed. Now anytime I try to move bitcoin from my ledger Nano S for any purchase this same sequence happens. I am not able to move btc without any remaining funds being attempted to be sent to an unknown address. I tried to move all my Bitcoin to a new account within the wallet, but each attempt fails. I have not tried to move my other coins (Bitcoin Cash and Ethereum) but fear the same thing may occur. I sent an email to Hashflare and to Ledger but responses will be 1-3 weeks.
Possible solutions?
My only thought and plan at the moment is to order a Trezor and move all but a very small amount over from the Ledger to the Trezor and allow the tiny amount that I don't send over go through to the unknown address. Good idea? I already bought a Trezor and it is on the way.