Conmitch

Evening all’ my 2008 a3 dsg gear box doesn’t change from second to the third to clarify I have to do the gears manually for all gears above third and once in said gears I never stay in them the car downshifts by itself sporadically however this all changes when I get an abs/esp fault and the lights come on the dash once this happens the car changes every gear perfect it never downshifts any clue why this is? Help would be appreciated.