Sounds like defective paint to me. This is happening a lot these days as EPA requiremnets force manufacturers to change the type of paint they use. The new Lycoming engine in our airplane had to be removed and sent back to the factory twice because the paint wouldn't stay on (and it is important for corrosion protection). Lycoming had to stop using the paint that they had used with great success for about 50 years. In our case Lycoming paid all the costs. Good luck with ML Quest.
In general I have found it difficult to keep speakers in unblemished condition. Note that the ProSound folk cover their speakers with carpet. Maybe they are on to something.
In general I have found it difficult to keep speakers in unblemished condition. Note that the ProSound folk cover their speakers with carpet. Maybe they are on to something.