A number of items can have an impact on the single threaded performance depending on the workload.
BIOS and AGESA revision
BIOS CPU configuration
You can try disabling FMAX Enhancer and Performance Optimiser. Set PBO to enabled and Max CPU Boost Clock to 200MHz
13900KS / 8200MT CAS36 / ROG APEX Z790 / ROG TUF RTX 4090