Auto gearbox problems . S Type 2.7 L diesel auto. 2007

Good morning to all.

Jag S type 2007 2.7 Diesel with auto gearbox.  Running very well until - yesterday stuck in massive traffic queues in Gloucester. Short while in queue suddenly the car lurched and jumped forward realising the electronic handbrake. Caught it in time not to hit the car ahead. Gearbox then lurched the car a couple of times.  Dash came up with ABS fault, Elect hand break fault, Gearbox fault.  Queue number one went but car very slow on pickup.

Next queue and another couple of gearbox jerks. Still very slow pulling away with turbos spinning fast.

Left the queues and drove home ok but still with the gearbox fault showing and ABS fault as well.

Home - left car for an hour - went out and tried it but still the same but only gearbox fault showing up, no ABS fault.

Left overnight, tried this morning, car running perfectly, no faults, everything back to normal!

Second time this has happened although this time worse than previously - is the gearbox overheating as it only seems to happen in traffic queues, never on the open road?

Had new oil, filter and sump (kit) fitted to the gearbox just after I bought the car, a few months ago by local all makes garage but gearbox would only take 3.5 litres of oil.  Could it be that there is not enough oil to keep the gearbox cool although the garage did seems to know what they were doing and it was an ex- Jag technician that did the work so he should know what he was doing. Reason for the gearbox oil change was simply that the car had done 70k miles and was 17 years old when I bought it.

HELP, HELP!

Geoff.