Video settings on OpenATV 7.x


I use my VU+ Zero 4K with OpenATV 6.4 image on my Samsung Q90T television. I have best picture on both SDR and HDR content while the automatic resolution is set to native in video settings and Input Signal Plus is enabled on tv for the corresponding HDMI input.
Otherwise if I use for example 2160p, then with Input Signal Plus enabled SDR content has worse colours, with Input Signal Plus disabled the HDR content. When I use 7.x image then with native setting I have weird fps displayed both on VU+ and on the tv as weel. For example on VU+ 51 Hz instead on 50, and on tv 60fps instead of 50.
Is there any solution ti solve this, either to use native or other (2160p / 2190p30 etc.) settings on video auto resolution?