Do you use the plugin mode (access via HTTP) or the direct mode (access directly via SMB)?
Music libraries are a mess in plugin mode.
Still not the best UI in the world but it’s the only Jellyfin player I found that can do seamless refresh rate switching, HDR playback, audio passthrough and has no issues with high bitrate 4k60 hardware decoding.
SMB works on all operating systems, my server runs on Linux and Kodi also runs on Linux. (NFS is also supported)