The correct answer is:
Alexa’s opponent was right, and the serve is a let.
From ITF Rule 22:
According to Rule 22, a serve is a let if “after touching the net…[the ball] touches the receiver or the receiver’s partner...before hitting the ground.” Even though a ball touching a player is usually grounds for that player losing the point, in the case of a serve touching the net and then a player, the serve is a let.
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