iMac RAM speed not displayed accurately

Hello.

I just got a 2020 iMac, and was planning on upgrading the RAM myself, but the clock speed isnt being displayed accurately. When it arrived with the Apple Ram(8GB), under "about my Mac", it displayed the ram as 2133MHz, which was different from the advertised 2667MHz. Furthermore, I also bought 32GB of additional "3200MT/s" RAM from here: https://www.amazon.com/gp/product/B08C4X9VR5/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I took out the 8GB of RAM that came with apple, since I know that would downclock my new RAM. Now, however, Apple "about my Mac" displays my new RAM as 2667MHz, while I was expecting 3200MHz.

I worry that my RAM clock speed is not running at its full potential, and I would like it to for X-Plane 11(for the frame rate). I read somewhere that an upgrade from 2667MHz to 3200MHz would increase FPS by about 30%, but I barely noticed an FPS increase if any.

Am I missing something here? Is the "3200MT/s" RAM supposed to show as 2667, and the 2667 show as 2113? Why is my iMac displaying them wrong?

I read somewhere that the new 2020 iMac was compatible with 3200MHz RAM, as seen here: https://www.reddit.com/r/mac/comments/i5i5js/the_new_2020_imac_has_3200mhz_memory_support/

Any insight would be appreciated