I recently made an animation for a paper I'm doing and I timed it out in Animate so it didn't seem too rushed as it's only six seconds. However, when I imported it into After Effects, it was playing faster though when I timed it, it was playing accurately at 6 seconds. Was something wrong with my original Animate document that caused it to play at a slower speed? I've ensured both files are at 25 frames per second. This is very frustrating as the animation has come out looking rushed.
Without more specific info nobody can tell you much. You are being generic and vague. Start by checking your project settings and publish settings in Flash/ animate and your footage interpretation in AE.