I am a new seller, selling via FBA, and initially I was getting the buy box and was able also to drive sales with PPC. Suddenly, despite there apparently not being a problem with my account, sales and PPC impressions disappeared. Went through automated help, and only then did it let me know that I am eligible for the buy box. "support" were hopeless, just giving me a stock answer about the factors which Amazon is prepared to disclose that drive eligibility.

Is this just something that happens to new sellers and I can just wait it out until eligibility returns or is my account cooked? Right now not making a single sale so if additional sales volume is a factor is regaining eligibility that is going to be basically impossible, particularly as I am already 40% cheaper than the seller who actually now has the buy box.