SOLVED: need help with hardware accelerated transcoding using AMD card

[physicsme]

I'm using Jellyfin on a Truenas Scale system via virtualization.
I'm having trouble transcoding stuff using an AMD card. Nvidia is working just fine on the same installation.

Here's the transcode log:

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -analyzeduration 200M -probesize 1G -init_hw_device drm=dr:/dev/dri/renderD128 -init_hw_device vaapi=va@dr -init_hw_device vulkan=vk@dr -filter_hw_device vk -hwaccel vaapi -hwaccel_output_format vaapi -noautorotate -i file:"(filename redacted).mkv" -noautoscale -map_metadata -1 -map_chapters -1 -threads 0 -map 0:0 -map 0:1 -map -0:s -codec:v:0 hevc_vaapi -tag:v:0 hvc1 -rc_mode VBR -b:v 36433184 -maxrate 36433184 -bufsize 72866368 -profile:v:0 main -sei -a53_cc -force_key_frames:0 "expr:gte(t,n_forced*3)" -flags:v -global_header -vf "setparams=color_primaries=bt2020:color_trc=smpte2084:colorspace=bt2020nc,hwmap=derive_device=vulkan,format=vulkan,libplacebo=upscaler=none:downscaler=none:format=bgra:tonemapping=bt.2390:peak_detect=0:color_primaries=bt709:color_trc=bt709:colorspace=bt709,hwmap=derive_device=vaapi,format=vaapi,scale_vaapi=format=nv12" -codec:a:0 libfdk_aac -ac 6 -ab 640000 -copyts -avoid_negative_ts disabled -max_muxing_queue_size 2048 -f hls -max_delay 5000000 -hls_time 3 -hls_segment_type mpegts -start_number 0 -hls_segment_filename "/cache/transcodes/946755f83897f1da43a30c43a8d82787%d.ts" -hls_playlist_type vod -hls_list_size 0 -y "/cache/transcodes/946755f83897f1da43a30c43a8d82787.m3u8"

.........
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Stream mapping:
  Stream #0:0 -> #0:0 (hevc (native) -> hevc (hevc_vaapi))
  Stream #0:1 -> #0:1 (dts (dca) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[hevc_vaapi @ 0x55c275cc5900] No usable encoding entrypoint found for profile VAProfileHEVCMain (17).
[vost#0:0/hevc_vaapi @ 0x55c275017e00] Error initializing output stream: Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
[libfdk_aac @ 0x55c274faf940] 2 frames left in the queue on closing
Conversion failed!

Here is my vainfo output :

Code:

Trying display: drm
libva info: VA-API version 1.22.0
libva info: Trying to open /usr/lib/jellyfin-ffmpeg/lib/dri/radeonsi_drv_video.so
libva info: Found init function __vaDriverInit_1_22
amdgpu: os_same_file_description couldn't determine if two DRM fds reference the same file description.
If they do, bad things may happen!
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.22 (libva 2.22.0)
vainfo: Driver version: Mesa Gallium driver 24.0.9 for AMD Radeon RX 6400 (radeonsi, navi24, LLVM 16.0.6, DRM 3.54, 6.6.32-production+truenas)
vainfo: Supported profile and entrypoints
      VAProfileH264ConstrainedBaseline: VAEntrypointVLD
      VAProfileH264Main              : VAEntrypointVLD
      VAProfileH264High              : VAEntrypointVLD
      VAProfileHEVCMain              : VAEntrypointVLD
      VAProfileHEVCMain10            : VAEntrypointVLD
      VAProfileVP9Profile0            : VAEntrypointVLD
      VAProfileVP9Profile2            : VAEntrypointVLD
      VAProfileNone                  : VAEntrypointVideoProc

I'm aware that there's no encoding profile. What could lead to this problem?