Skywatcher gave me a new scope and it is certainly better than the last but I am still disappointed. I put three different cameras on it with completely different spacers to rule out tilt from anything after the flattener and they all have the same issue with an asymmetrical halo on bright stars These cameras have no issue on my AT60ED. Below is a pic comparing them on the Esprit where I only adjusted the left side of the histogram. I guess I got another dud? I'm really frustrated right now.
Sorry to hear about your frustrations. I had this exact problem where stars "flared" out in one direction. I reached out to them and they sent me a replacement (took 3 months unfortunately as they had sold out over the holidays). I got lucky with the replacement as it no longer had this issue, but while waiting I ended up buying an alternative scope which I'm now using going forward for wide-field, so will probably just cut my loses and sell the Esprit.
Anyway, I know this doesn't really help you, but you're not alone. I would reach out to them again with this evidence, and I hope you're lucky on the 3rd replacement.