There is a mistake from row 10, errata below:

Rnd 10: sl st across to next 1ch sp, 3ch, (1tr, 1ch, 2tr) into same 1ch sp, @ miss 3ch, (3ch, 1dc into next 3ch sp) 5 times, 3ch, @@ work (DV st, 1ch), into each of next 3 1ch sps; rep from @, ending last rep at @@, work (DV st, 1ch) into each of next two 1 ch sps, join with sl st to top of first ch

Rnd 11: sl st across to next 1ch sp, 3ch, (1tr, 1ch, 2tr) into same 1ch sp, 3ch, @ miss 3ch, (1dc into next 3ch sp, 3ch) 4 times,@@(DV st into 1ch sp of next DV st, 3ch) 3 times; rep from @, ending last rep at @@, (DV st into1ch sp of next DV st, 3ch, ) twice, join with sl st to top of first ch

Rnd 12: sl st across to next 1ch sp, 3ch, (1tr, 1ch, 2tr) into same 1ch sp, @ miss 3ch, (3ch, 1dc into 3ch sp) 3 times, 3ch, DV st into1ch sp of next DV st, 11dtr into 1 ch sp of next DV st, @@ DV st into 1ch sp of next DV st; rep from @, ending last rep at @@, join with sl st to top of first ch