[HELP] 4K HDR x265 to 1080p SDR AV1

[LuCa4S]

Hello,

I have problem with conversion 4K HDR10 x265 to 1080p SDR AV1.
Almost everything works perfectly fine, but I can't achieved SDR colors.
I tried Filtering->Vapoursynth->Color->HDR to SDR->HDR10ToSDR but it doesn't effect. 
I tried also ToneMap setting, but I only enable it. I didnt change anything so... it also dont make effect
After conversion source and output videos looks the same.


I found this thread:

https://forum.selur.net/thread-249.html

But settings are completely different for AV1 codec. 
If I may please some guide to make through this. My ideas end

I'll be grateful for any help.

Greetings
PS: Sorry I forgot. I using Windows 10 and newest hybrid (today downloaded) version.