After many years of dealing with moulds and ear infections, every single new mould gave me sores, especially the ear tunnel part. The only thing that works is to coat the mould with Neosporin for one week, and after your ear gets used to the new mould, the sore spots go away. The mould company is not responsible for your issues, as all they do is make it from the impression that your audi made.
Warning: Anything I post may not make any sense. All advice is for entertainment value only. Sarcasm might be present. Interpret at your own risk.