The deal for Deportivo's Andone fell through, so the Seagulls switched their target to Spurs' Janssen as the 11pm deadline was nearing.
The club asked for a two-hour extension to complete the deal but, even though the two clubs had agreed a fee, the player rejected the personal terms and the move collapsed.
Meanwhile, Richie Towell has joined Rotherham United on loan for the rest of the season.