san no ito hit and resonance different

I recently noticed there is a noticeable difference between when i hit the ichi no ito and when it rings (resonates). I checked with a tuner and its only 0.9htz, but its sorta bugging me lately.

The other two strings are fine and disabling the suwari fixes it. Does anyone know what might be causing this?, or is it normal behavior and I’m just tuned into it now?