I don't have the pattern but someone else here may. If not, perhaps you could scan just the first few rows of the chart and post them. Yes, it's the usual way to set off a repeat on a chart, to box it in. Work the sts before the box, repeat the boxed sts however many times needed and then work the final sts on the left to the end of row.
There are a couple of things to check. Are you counting the actual sts across the row and not just the boxes? Count the sts you should have in the previous row according to the chart, then do the same for row 3. Count the increases across the row and count the decreases across the row, noting any double or triple increases or decreases.