Generic vs. Brand name Vyvanse

Has anyone else noticed a significant difference between generic Vyvnase (LISDEXAMFETAMINE) and brand name Vyvanse? the pharmacy told me that there is no difference other than the generic being much cheaper to buy. However my Doctor told me that there is a difference in how it personally affects you.

Just wondering if anyone can confirm that they are indeed much different from each other.

I’ve tried both now and it’s hard to say personally, I think the generic makes me feel more groggy, much more suppressed but it might just be a placebo. 🤷🏻‍♂️