What's causing my transcode error?

Client: Roku client 3.0.10 Server: 10.10.7 on Debian Trixie kernel 6.12.48+deb13 amd64 except this time it’s a Samsung R480 instead of the 2017 Intel Macbook Pro I usually use. Which means…
Hardware Acceleration engine VAAPI, vainfo already advised me to only use H/A for H264 and MPEG2.
Still, I can’t get it to work. What am I doing wrong?
Output:
  built with gcc 14 (Debian 14.2.0-19)
  configuration: --prefix=/usr/lib/jellyfin-ffmpeg --target-os=linux --extra-version=Jellyfin --disable-doc --disable-ffplay --disable-static --disable-libxcb --disable-sdl2 --disable-xlib --enable-lto=auto --enable-gpl --enable-version3 --enable-shared --enable-gmp --enable-gnutls --enable-chromaprint --enable-opencl --enable-libdrm --enable-libxml2 --enable-libass --enable-libfreetype --enable-libfribidi --enable-libfontconfig --enable-libharfbuzz --enable-libbluray --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libopenmpt --enable-libdav1d --enable-libsvtav1 --enable-libwebp --enable-libvpx --enable-libx264 --enable-libx265 --enable-libzvbi --enable-libzimg --enable-libfdk-aac --arch=amd64 --enable-libshaderc --enable-libplacebo --enable-vulkan --enable-vaapi --enable-amf --enable-libvpl --enable-ffnvcodec --enable-cuda --enable-cuda-llvm --enable-cuvid --enable-nvdec --enable-nvenc
  libavutil      59. 39.100 / 59. 39.100
  libavcodec     61. 19.101 / 61. 19.101
  libavformat    61.  7.100 / 61.  7.100
  libavdevice    61.  3.100 / 61.  3.100
  libavfilter    10.  4.100 / 10.  4.100
  libswscale      8.  3.100 /  8.  3.100
  libswresample   5.  3.100 /  5.  3.100
  libpostproc    58.  3.100 / 58.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '..../Videos/TV Shows/Ladies.of.the.Palace.2001/Ladies.of.the.Palace.S01E123.1080p.WEB-DL.H264.AAC-AppleTor.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
    creation_time   : 2016-02-17T18:12:32.000000Z
  Duration: 01:00:05.67, start: 0.000000, bitrate: 5259 kb/s
  Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 4998 kb/s, 29.97 fps, 29.97 tbr, 30k tbn (default)
      Metadata:
        creation_time   : 2016-02-17T18:12:32.000000Z
        vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 253 kb/s (default)
      Metadata:
        creation_time   : 2016-02-17T18:12:32.000000Z
        vendor_id       : [0][0][0][0]
[Parsed_subtitles_4 @ 0x7fdcda081100] libass API version: 0x1704000
[Parsed_subtitles_4 @ 0x7fdcda081100] libass source: commit: 0.17.4-0-gbbb3c7f1570a4a021e52683f3fbdf74fe492ae84
[Parsed_subtitles_4 @ 0x7fdcda081100] Shaper: FriBidi 1.0.16 (SIMPLE) HarfBuzz-ng 10.4.0 (COMPLEX)
[Parsed_subtitles_4 @ 0x7fdcda081100] Using font provider fontconfig
[AVHWDeviceContext @ 0x7fdcda081340] libva: /usr/lib/jellyfin-ffmpeg/lib/dri/iHD_drv_video.so init failed
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (h264_vaapi))
  Stream #0:1 -> #0:1 (aac (native) -> mp3 (libmp3lame))
Press [q] to stop, [?] for help
[Parsed_subtitles_4 @ 0x7fdcce4183c0] libass API version: 0x1704000
[Parsed_subtitles_4 @ 0x7fdcce4183c0] libass source: commit: 0.17.4-0-gbbb3c7f1570a4a021e52683f3fbdf74fe492ae84
[Parsed_subtitles_4 @ 0x7fdcce4183c0] Shaper: FriBidi 1.0.16 (SIMPLE) HarfBuzz-ng 10.4.0 (COMPLEX)
[Parsed_subtitles_4 @ 0x7fdcce4183c0] Using font provider fontconfig
[Parsed_subtitles_4 @ 0x7fdcce4183c0] fontselect: (Arial, 400, 0) -> /usr/share/fonts/truetype/msttcorefonts/Arial.ttf, 0, ArialMT
[Parsed_subtitles_4 @ 0x7fdcce4183c0] fontselect: (Times New Roman, 400, 0) -> /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman.ttf, 0, TimesNewRomanPSMT
[h264_vaapi @ 0x7fdcda0d0180] No usable encoding entrypoint found for profile VAProfileH264High (7).
[vost#0:0/h264_vaapi @ 0x7fdcda1f9600] Error while opening encoder - maybe incorrect parameters such as bit_rate, rate, width or height.
[vf#0:0 @ 0x7fdcda080d40] Error sending frames to consumers: Function not implemented
[vf#0:0 @ 0x7fdcda080d40] Task finished with error code: -38 (Function not implemented)
[vf#0:0 @ 0x7fdcda080d40] Terminating thread with return code -38 (Function not implemented)
[vost#0:0/h264_vaapi @ 0x7fdcda1f9600] Could not open encoder before EOF
[vost#0:0/h264_vaapi @ 0x7fdcda1f9600] Task finished with error code: -22 (Invalid argument)
[vost#0:0/h264_vaapi @ 0x7fdcda1f9600] Terminating thread with return code -22 (Invalid argument)
[out#0/hls @ 0x7fdcda080ec0] Nothing was written into output file, because at least one of its streams received no packets.
frame=    0 fps=0.0 q=0.0 Lsize=       0KiB time=N/A bitrate=N/A speed=N/A    
Conversion failed!