Question A6 Quattro S line 2006 - Stalling until perhaps engine warms up

Hi All. I hope you can help me please?

Just before Christmas I bought an A6 Quattro S line 06 plate. 2.7l auto tiptronic.
Recently when I start it, and then set off, it will stall after a few yards. It then does this repeatedly until what may be the engine warming up but thats not a definite....
I have ran the car idle for over 20 minutes and it doesn't stall except once, although it was and it was freezing outside that time. It still stalled when I set off. Same if I rev it for a while.
Usually, but not always, the glow plug light comes on.

When it stalls, revs drop to 0 and power steering fails. So I stop, put it in park, put on parking brake, turn off engine and then back on. This then repeats for a few attempts and then is ok.
MMI/dash panel don't turn off. The Battery indicator is full. No smoke coming from exhausts. It doesn't run lumpy. And no battery or engine warning lights come on.
I have tried setting off in Sports mode. Still stalls
I have tried reversing, still stalls.

I know hardly anything about engines, so don't even know where to start. So it may be basic maintenance needed? Or perhaps glow plugs do need replacing?

I expect I may need to take it to a garage for a VCDS/VAG reading, but with lockdown I can't at the moment.

I have went through quite a few of the pages in this A6 forum but not seen anything with exactly same issues. I went through over 70 of the 300 pages so there may be something before 2017 but thought I would post this while I keep looking.

Any help or suggestions would be appreciated.

Thanks in advance
HAK

Car Specs decoded from VIM & options sticker:

General Information
Make Audi
Model A6
Model year 2006
Body style 4 Doors Sedan
Vehicle class Large Car
Vehicle type Passenger car
Manufactured in Germany
Vehicle specification
Body type Sedan
Number of doors 4
Number of seats 5
Anti-Brake System ABS
Standard equipment
Stability control
AM/FM radio
Power Steering
Fog lights
Power door locks
Power windows
Front air conditioning
ABS brakes
Alloy wheels
Optional equipment
Traction control
Trip computer

E4J = "S-line"
7GN = Emission standard, EU4, DPF preparation
4UF = Drivers and front passenger air bag with front passenger air bag deactivation
6XK = Exterior mirrors: automatically dimming,electrically foldable/adjustable/heated
5SJ = Left exterior mirror: convex
6TS = Right exterior mirror: aspherical, large viewing field
1KW = Disc brakes, rear
J0Z = Battery 520 A (110 Ah)
1ZL = Disc brakes, front
1BV = Sports suspension/shock absorption
3FA = Without roof insert (standard roof)
5TG = Decorative aluminum inserts, dulling
7X0 = Without park distance control
F0A = No special purpose vehicle, standard equipment
8GV = Alternator 180 A
0G7 = Tiptronic
0YH = Weight range 8 installation control only, no requirement forecast
0JK = Weight category front axle weight range 10
TA1 = 6-cylinder diesel engine 2.7 L unit 059.F
3NZ = Rear seat bench unsplit, backrest split folding
8BF = Halogen headlight for driving on the left
U1B = Instrument insert with mph speedometer, clock, tachometer and trip odometer
X2B = National sales program Great Britain
1N3 = Speed-related variable steering assist (Servotronic)
2FQ = Leather trimmed multi-function sports steering wheel w/ Tiptronic
8Q1 = Headlight-range adjustment
9Q4 = Multi-function display/on-board computer with check control
8Z5 = Not hot country
D1N = 6-cyl. turbo dies. eng. 2.7 L/132 kW 24VV6 TDI, common rail base engine is TA1
7Q2 = Navigation system with color screen
CH9 = Alloy wheels 8J x 18
7K0 = Without tire pressure warning light
4X3 = Side air bag front with curtain air bag
2K7 = Reinforced bumpers
3L3 = Manual height adjustment for front seats
4KC = Side and rear windows in heat-insulating glass
3Y0 = Without roll-up sun screen
4K2 = Radio remote controlled central locking "SZV"
5D7 = Carrier frequency 868 MHz without panic button
1SA = Without additional front underbody guard
Q1D = Sports front seats
4GP = Windshield in heat-insulating glass with sunshield and viewing window for vehicle identification number