When I was studying for my CELPIP exam I got material from them. Unfortunately, I can not put the PDF to the public because it has a watermark with my personal email. But I can put you here what it says.
CELPIP's twentieth-second error as they state:
The transition terms are words and phrases that help the reader or the listener follow your narrative and connect your ideas together. They are like traffic signals, alerting the reader or listener to what might come next. There are three areas where errors most often occur on the CELPIP test in relationship to transition terms:
Using the same term repeatedly: