I just received my CAC-1085 and I have been having problems running at 4K120. It seems a lot of the time it is fine but if the screen is turned off and back on it will very likely have a distorted picture. Unplugging the adapters power and plugging it back in will usually solve it. It may take more than 1 power cycle to do it.
Here is what it looks like when it does this.
I know it will work fine at this setting as here is when it is fine.
I have tried multiple power adapters thinking that was the issue but it is not. I am currently using an Aukey USB-C cable and Aukey 20W power adapter. I also use a Cable Matters 6.6ft cable which is rated for 48Gbps and works fine when tested on a PS5.