Jon.
I had the same problem on my 2018 Q8, which was extremely bad.
i escalated my issue the the Managing Director of Audio UK, as my car was not in warranty, they offered me to replace all the lights for a contribution of £1500.00, if it was under warranty they would have completed the replacement for free?
I have now raised my issue to Audio Global, which is an going matter.
I replaced all my re lights for inder £900.00 by shopping around (part new part second market in excellent condition).
I hope this helps, reach out to me if you would like further information.