Well, I’ll offer a geezer’s 20+ years of insight. Nothing at all is wrong with your parameters. Changing any parameters right now can just about assure whatever SPS are left won’t be for long.
I looked at your equipment list and didn’t notice a very critical component of keeping SPS. FLOW. Do you have any flow whatsoever in your tank other than the return pump? See, when you add that much energy (light, food, available nutrients) and don’t have enough flow for SPS corals, they basically can’t “breathe”. So basically all that energy you’re giving them requires them to process it and release byproducts of waste. Unfortunately SPS corals simply can’t do that on their own without an adequate current to help remove that waste and bring new nutrients to them.
Your nutrients are on the high side...but they’re fine. To keep your nutrients there you must match both the lighting and the flow. I’d keep the lighting where it is for now. But adding a (for lack of a better term) **** TON more than what you’re providing in a random and chaotic pattern of flow is essential. And I mean move enough water so that sand moves and every inch of that cube is visibly showing water movement.
my .02