Dnasty

I've been having issues with brake squeal on my car for about a year now and have been able to identify the noise to only coming from one wheel on the car. The passenger side has the same pads (new) and rotors oems bought about 2 months ago and makes no noise. But almost every stop I come to I hear a loud brake squeal coming from only the drivers side front tire section (at times it makes somewhat of a fluttering squeal).

I am not really sure what to make of this, I took the brakes apart many times.. cleaned caliper applied all types of pastes.. shims.. etc...

Could this just be a bad caliper? Or could there be an issue with the abs? I have no lights on in the car and braking is actually fine (feels very safe). Just cannot escape this noise.