LCQ514

My 2014 Q5 has had intermittent starting problems since June (2019). It usually happens after the car has been used and then parked. It's never happened on the first cold start of the day. After being driven it could be parked for 10 minutes or hours at a time and on occasion when I go to start it again, it will either not turnover at all or it starts to turnover initially but I need to put my foot on the gas to get it to fully connect and start. For the times when it doesn't start at all,I I try again & that's when it will initially start to connect but not fully & I have to put my foot on the gas. I should say that each time this has happened, it does eventually start. At first I thought it was heat related b/c it happened when it was very hot & humid out, however, it's continued to do this even with the Fall & cooler weather. It doesn't happen all the time but it can happen once to multiple times a day. I've brought it to an Audi dealer and to a mechanic who specializes in foreign cars. It didn't happen either time and so they could not diagnose what was wrong. The battery & starter were both checked each time and were fine. My CPW is up in May 2020 and I'd really like for this to get resolved before then as I feel it is a defect that Audi should/could fix. Does anyone have any insight as to what could be causing it and what I should do?