A couple of thoughts...

1. Silly question, but is it definitely rosemary?
2. Young growth is usually less intense than older.
3. Are you watering/feeding it and making it too lush and sappy?

If you take the pieces closer to the bottom instead of the top is there more flavor there? What are you using it in that you notice it lacks flavor? When I chop rosemary for a rub the flavor is less intense than if I infuse it in my olive oil.

If it's not getting much sun, it's not manufacturing the essential oil in the leaves which give it its pungent smell and taste. Rosemary likes full sun, as hot as it can get, and as much as it can get.

Also, like many of the Mediterranean herbs, a soil which is too rich will 'dilute' the flavour. These plants prefer poor soil - they like to work hard! So don't fertilise. A handful or two of compost once or twice a year is quite sufficient, and if you forget - the plant will still soldier on for many years.

And yes, don't eat any more of it until you are 100% sure you've got an edible plant. There are many rosemary look-alikes.