I agree that Club 3D makes ones that actually work!
This is the one I have and it works at 4K with HDR 60fps.
Club 3D CAC-1080 DisplayPort 1.4 to HDMI 2.0B HDR Adapter Supports 4096X2160@60Hz High Dynamic Range
https://www.amazon.com/gp/product/B077JB28KM/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Be careful they currently make 3 versions. This is the best one at the moment 2/2020. As it is 2.0B and HDR compatible.
Realtek is working on a new chip for a converter that will be 8K 60hz with HDR but it won't be out for a month or 2. I think it is supposed to support 4K at 120hz. So it really depends on the monitor or TV you are going to use as to what you have to have. For instance most any of them will work fine at 1080p 60hz with no HDR if they are labeled as active adaptors. Most though will not give you more than 30hz at 4K. The club 3D ones do, but the lower models don't do HDR.