No, you didn’t listen carefully enough. When I talk about “reinvesting”, I’m talking about Treasury Bills, which mature in 13 or 26 weeks.
You do NOT reinvest I-bonds. The rate you are paid automatically changes every 6 months, and there is nothing you can do about that. You should plan to hold them for at least 5 years to avoid a 3-month loss of interest penalty for getting out early.