hi guy, ill try to make this as short as possible

i work at a small used car dealership, i got a 1996 audi cabriolet, the car had problems shifting, took it to a local transmission shop, and they rebuilt the tranny and changed the valve body, now it shifts fine with only 1 major problem

when put in D (or 1st) it dosent go into gear till i rev the gas for a little bit, same when coming to a stop after driving, the first gear dosent engage till i give it some gas, the transmission shop couldn't figure out what the problem is so they didnt charge me for the repairs.

i tried to do some research online but i didnt find anyone with similar problem, i found some threads that suggest that the TCM might have problems with these models, but is there is anything else i should check before replacing the TCM?