Then tried the disable over ride and that worked
As I've said, I tried to enable the override, and it doesn't make any difference here, tractor is visible in both cases except, of course, when the override is used, the tractor has the livery of the operator set in the override page, as it should.
tractors back but it is the wrong provider at the gate (British Airways livery at gate 8 in EGPH).
What do you mean with "wrong" provider ? British Airways is one of several operators assigned to that airport, together with IAG, BMI, EZY, Servisair and Menzies at equal priority and, if the scenery you use had BA parking codes, and no code of the others, BA is the correct operator in this case.
If you mean "wrong compared to real life", you can always customize the parking to assign a different one.