Disable both low power encoding options. That requires additional firmware that, AFAIK, can't be installed on DSM. It is optional anyway. Regardless, IIRC Gemini Lake only supports H264 low power encoding anyway.
Jellyfin 10.10.0 (Docker)
Ubuntu 24.04 LTS
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
3x WD Red Pro 6TB CMR in RAIDZ1 (JF Library)