DDJ-SX3 Loud Beep, Sound Issues, Crashes

So a very disappointing experience with my brand new DDJ-SX3, which I was so excited about getting. I've been an avid Pioneer fan for ages, owning CDJ-100s, CDJ200s, DJM-700, DDJ-S1, DDJ-ERGO, S-DJ80X, and now the disappointing DDJ-SX3. Let me share my experiences from this past, very painful month of gigs and embarassment.

Running Serato v2.5.9 (latest) on 64bit Dell Inspiron 5406 with Windows 11, 16Gb RAM, i7 processor. Firmware 1.02 and Windows driver 1.010.

I have not had a 'clean' set where I haven't experienced one of the following:

1. USB Audio dropouts (Serato-related, but have rectified these with ASIO buffer settings, screen res and updates, etc)
2. The dreaded loud obnoxious BEEEEEEEP before the controller shutting down.
3. Random 1 to 2 second long distortion sounds coming through main / booth outputs, on any channel (1 / 2 / 3 / 4), any input (USB-A / USB-B / Line In), not linked to Serato drop-outs
4. Continous over-headphone distortion sound for the duration of a track or two

To be short, this controller has been a disaster, and an embarassment, and a source of major stress and disappointment in my life over the past month of ownership (I bought it brand new, and it had the black dot on the serial barcode).

I have tried the following:

1. Master reset (SHIFT + DECK 1 then SYNC1 + SYNC2)
2. Different USB cable
3. Different USB port
4. USB A vs USB B
5. Different decks / line inputs
6. Stand-alone (no USB connected) with line in only
7. Laptop plugged into AC and laptop running on battery only

Has anyone got a solution or experienced similar issues? I'm otherwise looking at getting a full refund and getting a Denon MC6000MK2 as it's got the same features. It's a pity because I just love Pioneer products, I think this series is just a disaster.