Last year our primary teacher couldn't spell, I assumed that it was a one off. It's happened again this year with a different teacher. The teacher commonly changes the correct spelling for an incorrect one it seems, separate to seperate, a lot to alot and so on.
Does it matter for Y2 or Y3? I haven't complained as I see no upside. Perhaps it really isn't important, no one values it so much any more, that much is clear.