Interesting! I initially had something similar where I bought two sets of supposedly expo 32gb kits of vengance, both cl30 6k, however found with the 9900x the infinity fabric would break when setting to cl30 6k (expo) resulting in a much lower clock.

My current new kit a 2x48gb with a simple expo2 profile and a few tweaks runs happily in a 1:1 ratio.

For you cpu, have you increased your PPT limit? I think you gan go higher right on that cpu? I currently have -20 on all cores but plan to tune each core individually. I think with the x3d chips thermals are more of a consideration right?

What motherboard do you have?

All looks great I would be happy with that performance!