Extreme Banding on Black parts

How can I get rid off this horrible banding? This was shot on Sony A7IV 4K XAVC S 10bit 200MM in SLog. After editing and color grading was exported in H264, Maximum Render quality, Maximum depth, High 5.1, CBR 60Mbps. I also tried QuickTime ProRes 422 HQ, 16 Depth and the banding almost disappears but my image gets significantly darker and contrasty. Also H265 with all the goodies setting but got even worst. Any good tutorials or tips?