The lot has been sold at my maximum bid, but not to me? How can this be?

To understand why you did not win the lot, even though the winning bid was at the level of your maximum bid, you need to consider that LOT-TISSIMO is only one bidding channel of the auction houses. The auction houses can still receive bids directly at the auction house itself, especially during a live auction in progress.

How does this situation arise?

This can happen if an identical maximum bid was placed by another bidder. The auctioneer decides to whom they award the lot in this stalemate situation.

There are different ways to place bids at auction houses. Either live during the auction in the room, or by submitting a written advance bid directly to the auction house, or as a telephone bidder, or by bidding live via LOT-TISSIMO during the auction, or by submitting a prior bid via LOT-TISSIMO (a written bid which the auctioneer does not know).