EK43s problem - chirps after grinding

Hi guys, I am having an issue with my EK43s and hoping someone here could help me with it. This issue has been bugging me for months, and I couldn’t find a solution for it.

Here’s a video of my problem

I’ve set the zero to about -0.5. From the video, the machine started ringing as soon as it grind some beans. When I turned the dial to a finer setting, all the way to zero, the grinder makes a chirping sound. And when I turned the dial to finer then coarser, the chirping stops until I put more beans through or restart the grinder. Before the grinder stopped completely, it makes a loud grinding sound.

I’d aligned the stationary burr to about 0.01mm with the Titus alignment tool. The shear plate was filled so that it sits completely in the carrier, suggested by Frank from Titus. I’d also replaced the burr carrier to the one from Titus. But nothing works. This is my second EK43s, the first one has the same problem too.