Happens with both H264 and HEVC.
This does not happen under ffmpeg. Either with H264 or HEVC.
Code
F:\Videos>ffmpeg -i F:\Videos\seg4.mp4 -pix_fmt yuv444p -c:v h264_nvenc -rc constqp -qp 3 -b:v 0K test0.mkv
ffmpeg version 2021-10-03-git-2761a7403b-full_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers
built with gcc 10.3.0 (Rev5, Built by MSYS2 project)
configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libglslang --enable-vulkan --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
libavutil 57. 7.100 / 57. 7.100
libavcodec 59. 10.100 / 59. 10.100
libavformat 59. 5.100 / 59. 5.100
libavdevice 59. 0.101 / 59. 0.101
libavfilter 8. 11.100 / 8. 11.100
libswscale 6. 1.100 / 6. 1.100
libswresample 4. 0.100 / 4. 0.100
libpostproc 56. 0.100 / 56. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'F:\Videos\seg4.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf59.5.100
Duration: 00:05:28.29, start: 0.000000, bitrate: 517899 kb/s
Stream #0:0[0x1](und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 517883 kb/s, 120 fps, 120 tbr, 15360 tbn (default)
Metadata:
handler_name : VideoHandler
vendor_id : [0][0][0][0]
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> h264 (h264_nvenc))
Press [q] to stop, [?] for help
Output #0, matroska, to 'test0.mkv':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf59.5.100
Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (H264 / 0x34363248), yuv444p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 120 fps, 1k tbn (default)
Metadata:
handler_name : VideoHandler
vendor_id : [0][0][0][0]
encoder : Lavc59.10.100 h264_nvenc
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame= 404 fps=175 q=2.0 Lsize= 288582kB time=00:00:03.33 bitrate=709076.5kbits/s speed=1.44x
video:288577kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001707%
Exiting normally, received signal 2.
F:\Videos>