So I just got my DF64v delivered today and it’s my first flat burr grinder.

I noticed that it’s quiet until I grind and then after grinding it’s making a louder squeal / humm. If I try to adjust finer there is resistance and the noise is much louder.

It seems like a boulder getting stuck on the non-moving (top) burr. I’ve taken it apart and cleaned it. It’s quiet again until I grind and then it has the same behavior.

RDT doesn’t seem to make a difference.

I’ve checked the alignment of the burrs and they are darn near perfect.

Is this normal for a flat burr machine (this is my first) or is something wrong?

I’m not trying to be picky - just never having had a flat burr and having never heard of this or seen this before in any of the review videos / reviews - I’m not sure if it’s normal or cause for concern.

The burrs look good / undamaged.

If this is normal no big deal - I just don’t know enough to know. My Google searching hasn’t turned up much.