N54 AFE Intake issues

[R3SQ]

A few weeks ago I removed and cleaned my AFE Intake filters. I reinstalled them just as before and figured there would be no issues.

Now, after the car is heated up there is a strange howling noise coming from the engine bay in between shifts. This occurs every time I let off the throttle and switch gears. It's not the regular "intake noise" you hear. But a more distinct howl/whine. The car is showing no codes and is boosting fine.

How likely is it that something got damaged/loosened up while removing and reinstalling the filters? Or is it possible I didn't check, like an idiot, to see if the filters were completely dry and are shot? It sounds to me like there is air escaping somewhere, but everything seems normal until I take my foot off the gas.

Thanks!