I did one extra wave but forgot to add the last row of sc. Might be why it’s a little wonky. Oops.

For the border I sc around (one sc in the side of each sc, two sc in the sides DC, 3 sc in each corner)

Ch1 and turn for second round of the border, sc, tr repeat (and in the corner sc, tr, sc in the 2nd of the 3sc in the corner)

Ch1 sc in each st