Does haste double longstrider movement bonus regardless of what is cast first?

@JeremyECrawford My group is trying to work something out; Does haste double longstrider movement bonus regardless of what is cast first?

— PawnRenegade (@PawnRenegade) September 12, 2017

While the haste spell is active, it doubles your current speed. If your speed changes, haste doubles whatever your new speed is. #DnD https://t.co/0PTVyw92Pe

— Jeremy Crawford (@JeremyECrawford) September 12, 2017