Issue with (probably) DSG and DPF

Hello,

I'll start with some basic information:
Superb 3, 2.0 TDI, DSG 6, 2017, CRLB, purchased at around 75k, current mileage is 200k. The car is mainly used for work as a taxi, averaging around 1000 miles per week.

I'll also list what I've replaced in the last 4-5 months, as one of these replacements might have caused a fault:

Engine oil and filters service roughly every 5-6 weeks

Gearbox service: oil and filter changed just over a month ago (I replace it approximately once a year)

Additionally replaced: battery, timing belt + water pump, driveshaft, EGR, differential pressure sensor, glow plugs, dual-mass flywheel (without clutch), CV joint, steering rack, tensioner, alternator belt.

Issues: While driving, the car occasionally drops from 2000 RPM to 1000 RPM for just a second before going back to 2000 RPM. This results in a jerk, as if it's running out of fuel, something is clogged, the gear disengages, or the power cuts out it’s hard to pinpoint.

Sometimes, right after starting and pulling away, the engine stalls. It has also happened while driving. Recently, while cruising on the motorway at 70mph on cruise control, the engine just switched off. I always disable the start/stop system when starting the car.

At least once a day, regardless of whether I’m driving in the city or on the motorway, several warning lights appear on both the infotainment screen and the dashboard:

Glow plugs (flashing constantly)

ESC

Tyre pressure monitoring system (low pressure)

Start/Stop

Parking assistant

Adaptive cruise control

The car goes into limp mode with limited speed. All warning lights disappear after switching the engine off and on twice, and everything returns to normal.

Fault codes:

Errors that appear before the warning lights:

Basic OBD2:

Infotainment system:

• 00005 - Connection between radio and antenna amplifier 1: Open circuit

• 00006 - Connection between radio and antenna amplifier 2: Open circuit

Heater & air conditioning:

• 263425 - Air quality sensor: faulty

Central electronics:

• 204546 - Remote control key 2: Voltage too low

Driver's seat:

• 10489856 - No basic setting

• 9654612 - Lumbar support height adjustment motor: No basic setting

• 9654868 - Lumbar support fore/aft adjustment motor: No basic setting

• 9655380 - Seat height adjustment motor: No basic setting

• 9655892 - Seat backrest adjustment motor: No basic setting

Errors that appear after the warning lights on the dashboard:

Basic OBD2:

ABS:

• 16410 - Tyre Pressure Monitoring System (TPMS): Signal malfunction

• 08296 - Databus error value received

Power steering:

• 22532 - Databus error value received

Infotainment system:

• 00005 - Connection between radio and antenna amplifier 1: Open circuit

• 00006 - Connection between radio and antenna amplifier 2: Open circuit

Heater & air conditioning:

• 263425 - Air quality sensor: faulty

Parking/steering assist:

• 13637426 - Databus error value received

Driver's seat:

• 10489856 - No basic setting

• 9654612 - Lumbar support height adjustment motor: No basic setting

• 9654868 - Lumbar support fore/aft adjustment motor: No basic setting

• 9655380 - Seat height adjustment motor: No basic setting

• 9655892 - Seat backrest adjustment motor: No basic setting

Adaptive cruise control:

• 02068 - Databus error value received

• 02101 - Databus error value received

• 02131 - Databus implausible message

I checked these errors using the Carista app, and to be sure, I also visited a friend who uses Launch x431 pro – he got exactly the same fault codes.

Another issue DPF regeneration frequency

For quite some time now, the DPF regenerates very frequently, approximately every 20miles in urban driving. Since owning the car, I’ve only seen the DPF warning light appear four times.

I assume regeneration is happening because, several times a day when idling, the RPM increases from 900 to 1000.

A few days ago on the motorway, I checked the live DPF data on my phone. At first, the soot level was around 3g for the first 60 miles, but in one second, it jumped to 20g, triggering a regeneration.

This may or may not be relevant, but I’ve attached a screenshot from VAG DPF, taken while idling.

I would be extremely grateful for any help, I have no idea where to start.