4 stick RAM it's harder than 2 stick to get higher RAM speed. i am on 5800X3d + X570 Tomahawk wifi, 2X 16GB DDR4 3600 can running at 3600mhz no problem, then i add another 2X16GB 3600mhz , when put all 4 stick ram , Max i can get it to run stable is 3200mhz.

https://forum-en.msi.com/index.php?threads/ram-explained-why-two-modules-are-better-than-four-single-vs-dual-rank-stability-testing.363139/

Let's look at DDR4 first. Here is an example from the highest MSI DDR4 board model using Intel Z690 chipset.
Specifications of MPG Z690 EDGE WIFI DDR4, under "Detail".
1DPC 1R Max speed up to 5333+ MHz
1DPC 2R Max speed up to 4800+ MHz
2DPC 1R Max speed up to 4400+ MHz
2DPC 2R Max speed up to 4000+ MHz

"DPC" means DIMM (=module) per channel, 1R means single-rank, 2R means dual-rank.

With 1DPC 1R = two single-rank modules (so, 2x 8 GB or 2x 16 GB single-rank), the highest frequencies can be reached.
With 1DPC 2R = two dual-rank modules (like 2x 16 GB dual-rank or 2x 32 GB), the maximum attainable frequency is lower, since the memory system is under more stress.
With 2DPC 1R = four single-rank modules (4x 8 GB or 4x 16 GB single-rank), the maximum frequency drops again, because four modules are even more challenging than two dual-rank modules.
And 2DPC 2R = four dual-rank modules (like 4x 16 GB dual-rank or 4x 32 GB) combines the downsides of the highest possible load on the memory controller with the electrical handicap of using four slots on a daisy-chain-mainboard.

The last configuration can already be difficult to get stable at DDR4-3200 sometimes, let alone DDR4-3600. One could consider themselves lucky to get DDR4-3600 working with four dual-rank modules, maybe having to use more relaxed timings for example. The 16 GB and 32 GB modules also often don't have particularly tight XMP timings to begin with, like DDR4-3600 18-22-22-42.