Ok, something is definitely not right. You don't have it too cranked at all.
Sorry if I forgot some info you already gave,
I don't always have time to go back over the whole thread and forget the details. I remember now that you said you had a DRRI before. But, if this amp was shipped from Ceriatone, I would feel it almost a necesassity to check the bias immediately just to be sure it didn't get moved somehow in shipping. Also, the first thing I would do with an amp that was shipped so far and not performing properly is start troubleshooting with known good tubes.
I don't think anyone is suggesting you're complaining over nothing. What has Nik suggested? He is excellent at responding to problems and questions. But you will have to follow his suggestions.
Finally, I can tell you that a bad tube can cause all kinds of strange problems that can be intermittent and very perplexing and the only fix is a good one in its place. It could be a failed component internally and that will be more complicated to figure out.
I hope you get it figured out.