Okay so with this being such a new tank, I have no doubt in my mind that your parameters fluctuate a good bit through the day. This is why most others recommend you wait for at least 6 months for your tank to “mature” before adding an Anemone. I understand you moved the rock over, which is great! You have a good bacteria population then. But the reason people say 6 months or so is because the longer a tank runs, the more the Chemistry of the water “tables out” you see little swings through the day instead of large ones. Creating more of a stable tank.
You are definitely on the right track to keep an Anemone in the future. But unfortunately right now it’s looking like an uphill battle. Just watch your parameters closely and make sure their is no big swings. Anemones like stability. And maybe turn your light down just a bit. Kessils can be a beast of their own sometimes.
-Zack, who is sending all the luck your way.