Interesting. The web client states in the "video" line that it detects that it is HDR. But when I look in the Android TV client there is no HDR tag. So I'm assuming that is what you are also not seeing in Kodi.
Jellyfin 10.10.3 (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)