Vehicle: 2013 M56S
Back in May I purchased a full set of pads from local Infiniti dealership in South Houston. Here are the current part #'s provided by them for my sport brakes:
D4M60-JL00A
D1M60-JL00B
Rotors from Advance Auto Parts:
CQPRT Brake Rotor YH247724P (Front) - w/RotorShield Protection
CQPRT Brake Rotor YH274985P (Rear) - w/RotorShield Protection
URL link to front Rotors: https://shop.advanceautoparts.com/p/cqprt/11401732-P

The pads were lost in shipment by FedEx for over a week (mainly due to spelling error from dealership on address) and when I finally got them, they were flopping around in the larger box with the individual boxes having been destroyed and a thick coating of brake dust over everything. There was some very minor chipping on some edges from them banging around against each other for a week. But the pad faces looked fine.

I had them installed by a local shop because my back can't handle doing these kinds of jobs anymore. When I picked it up, I could tell they had cleaned the rotors and actually "scuffed" the rotor surfaces in a cross-hatch pattern perhaps with some sandpaper or a wire brush.

The problem I am having is obnoxious brake squeal when backing out of driveway and at slow braking as I come to first couple stop signs in my neighborhood. This has no subsided in over two months. They stop great, no shimmy/shake/flutter and when warm don't squeal at all. I mostly drive short trips but even when the care sits for 20 minutes and they cool down they will squeal during slow light braking stops.

I have tried bedding the brakes one time with 8-10 hard braking events from 60mph-20mph in 95+ heat until I could smell the brakes. That did not help.

I stopped back by the shop that installed them and they pulled front wheel and everything looked proper. They said they spray the rotors to remove any Mfg. coating prior to installation. Rotors look smooth, no discoloration.

This is really getting embarrassing in my neighborhood, and I have never had a brake squeal problem like this in my life. Any suggestions on what I should do?

They probably installed them without grease, or at least only grease on the backs of the pads and not the shoulders. Nissan brakes are pretty infamous for squeaks and squawks if you lay the pads in dry.

Sounds like I need to pull them and add some grease.

Yep. Grease all the areas that move, particularly the "shoulder" tabs that ride in the grooves in the caliper bracket. Those are the most likely culprit to be causing your issue,

Update and closure on my above post… after cleaning and lube the pad assemblies the brakes still squeaked at first roll and any slow stops like at lights and parking etc. it was just the rear smaller brakes. Divided to get the “new” rotors turned. When I pulled the rotors. You can see where thy was uneven wear on the face. Definitely not true at all. Got them back and installed, no mor squeal. First time I’ve seen warped rotors out of the box. Both of the rear. Will try to post a pic of the wear.

That's pretty unusual without also getting a seat-of-pants brake pulsation, but maybe they were machined off center as opposed to running out. Either way, glad you got it straightened away!