Possible Turbo Flutter After Mishimoto TMIC Install

I recently installed a Mishimoto TMIC after my OEM one sprung a leak at the seal between the metal and plastic. I have verified that all hoses are hooked up and nothing seems to be leaking. When I only hit maybe 1-10 PSI of boost, there is no noise, except the BPV releasing pressure. When I start getting into the teens, there is both a release sound and a bit of what I think is turbo flutter. Has anyone else run into this? How do I fix it? (2010 WRX btw)

Edit: the sound is happening when I release the throttle after doing a pull and hitting ~12-19PSI