This is correct......because the oil is not up to operating temperature, it is still thick, and develops a surface tension between the metal plates and friction plates. Its like the clutch plates are a bit stuck together by just the cold oil.....its acting like the clutch is engaged still.
Its always best to start the bike in nutral, and you will avoid over stressing the starter motor unnecessarily. Once the engine is up to normal opp temp, this dont usually happen depending on the weight oil used....but I would still put it in N before starting.