I’ll be in touch very soon mate. In the meantime before I come please can you do me a favour. The engine MUST be stone cold for this

Using your fancy Bluetooth scanny thing, can you bring up the live data before the first start of the day, (so engine off and stone cold, but ignition on).
Find the value for coolant temperature sensor. Check that it’s reading at (or slightly above) the ambient outside temperature with a cold engine. (Make a note)
Then turn on the car, let it idle, and keep watching the coolant temperature reading. Run it to the point the fans kick in, and record the temperature again.
Also note any trends in the middle - eg, it should just go up a bit at a time with no huge rises or falls.
It might be in your live data as “CTS” or “coolant temp” or similar.

My thinking is that a faulty / erratic CTS can cause problems with the engine going from open to closed loop, which can make lambdas rather unhappy!