Hi. It’s so useful reading all these responses. It’s clearly a common fault with this car although mine is getting on now.Mine started playing up always when cold weather set in as lubricant gets thick and prevents lock module working correctly.
After a while the module suffers. Mine then went and I replaced it - part cost £100 from audi and it took 2 hours as I took my time. You need to get door card clips as they break. Easy job but takes time.