1 of 2 SSDs read slows down after windows fully boot. Please help, thank you

Question

I have encountered a weird problem. System Spec: Windows 10 Intel I9-9980 HK 16 GB Ram RTX 2080 16GB MAX-Q ADATA SX8200PNP 2TB SSD KXG50PNV2T04 2TB SSD

Two M.2 SSDs,