Miles & More (Lufthansa, Austrian, Swiss, and other partners) - mileage refund (against fee) then a green check mark

i was test booking an award iad-tls in biz class on lh. the fee is $648(i think) the next screen had a window stating "mileage refund against fee. any idea what they are tailing about. that fee was real for me when i flew iad-vie-vce ret on os. i did not get any mileage kisses or offers of such, that i recall.

Two different fees here methinks:
Your $648 would be LH's taxes and surcharges that they elect to part you with even for an award ticket.
The fee for a mileage refund refers to an admin charge they levy to redeposit your miles into your account in case you cancel the award ticket.