Authorization for cancelling an order is different for matching an order#
Works as intended.
cancel function simply requires
require(_msgSender() == order.maker, "not a maker"); for cancelling an order.
However orders can be authorized with
matchOrders by using
_msgSender() == order.maker or signatures from users or signatures from contracts.
So orders that are started with
matchOrders using signatures can't be cancelled using signatures.
However this is fine if this is the desired functionality.