Fixing credit after opening amex gold

Hey folks, new credit card user here. I opened up a new amex Gold account and I've had it for around 10 months. A couple weeks ago I saw that my credit score dropped 73 points around 6 months in.

I'm pretty confused how this could happen. I've always paid my balance on time. ChatGPT said to pay most of my balance before the statement closes, but that didn't result in any increase of my credit score upon the next pull. Any ideas how I could fix this? This is my only credit card account, and I'm considering opening a new card to help build my credit history but I'm scared of the score drop.